- Test - lists.nanog.org

Packet Loss on Level3
by Dustin Schuemann 21 Aug '09

21 Aug '09

Is anyone else seeing packet loss on Level3. 6. ge-6-11-137.car2.Detroit1.Level3.net 2.9% 35 372.1 148.6 19.4 704.8 127.4 7. ae-11-11.car1.Detroit1.Level3.net 8.6% 35 268.1 161.5 21.3 691.8 156.0 8. ae-8-8.ebr2.Chicago1.Level3.net 0.0% 35 173.6 142.8 34.5 532.4 117.1 9. ae-21-52.car1.Chicago1.Level3.net 5.7% 35 78.1 210.3 35.7 631.2 157.9

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Redundancy & Summarization
by Gaynor, Jonathan 21 Aug '09

21 Aug '09

My institution has a single /16 spread across 2 sites: the lower /17 is used at site A, the upper /17 at site B. Sites A & B are connected internally. Currently both sites have their own ISPs and only advertise their own /17's. For redundancy we proposed that each site advertise both their own /17 and the whole /16, so that an ISP failure at either site would trigger traffic from both /17s to reconverge towards the unaffected location. My worry/question: will carriers down the line auto-summarize my advertisements into a single /16, resulting in a 'load sharing' while both sites are active? If you're a backbone carrier and you saw x.x/16 and x.x/17 (or x.x/16 and x.x.128/17) being advertised from the same peer would you drop the longer match? Regards and thanks, Jon Gaynor, Senior Network Engineer Fox Chase Cancer Center (215) 214-4267, jonathan.gaynor(a)fccc.edu

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F5/Cisco catalyst configuration question
by Scott Spencer 20 Aug '09

20 Aug '09

Trying to link an F5 Local Traffic Manager with a Cisco Catalyst 6500 , have matched ports (speed,duplex ect..) but no link light at all on the F5. Does link with a Cisco 2950 switch in between but I need a direct connection with the 6500. Any suggestions what to try? Best regards, Scott Spencer Data Center Asset Recovery/Remarketing Manager Duane Whitlow & Co. Inc. Nationwide Toll Free: 800.977.7473. Direct: 972.865.1395 Fax: 972.931.3340 <mailto:scott@dwc-computer.com> scott(a)dwc-computer.com <http://www.dwc-it.com/> www.dwc-it.com Cisco/Juniper/F5/Foundry/Brocade/Sun/IBM/Dell/Liebert and more ~

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IPv6 Addressing Help
by Chris Gotstein 20 Aug '09

20 Aug '09

We are a small ISP that is in the process of setting up IPv6 on our network. We already have the ARIN allocation and i have a couple routers and servers running dual stack. Wondering if someone out there would be willing to give me a few pointers on setting up my addressing scheme? I've been mulling over how to do it, and i think i'm making it more complicated than it needs to be. You can hit me offlist if you wish to help. Thanks. -- Chris Gotstein Sr Network Engineer UP Logon/Computer Connection UP 500 N Stephenson Ave Iron Mountain, MI 49801 Phone: 906-774-4847 Fax: 906-774-0335 chris(a)uplogon.com

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Fwd: [Full-disclosure] Cisco Security Advisory: Firewall Services Module Crafted ICMP Message Vulnerability
by John Kinsella 19 Aug '09

19 Aug '09

FYI...I thought PSIRT sent security notices to nanog? Begin forwarded message: > From: Cisco Systems Product Security Incident Response Team <psirt(a)cisco.com > > > Date: August 19, 2009 10:12:26 AM PDT > To: full-disclosure(a)lists.grok.org.uk > Cc: psirt(a)cisco.com > Subject: [Full-disclosure] Cisco Security Advisory: Firewall > Services Module Crafted ICMP Message Vulnerability > > -----BEGIN PGP SIGNED MESSAGE----- > Hash: SHA1 > > Cisco Security Advisory: Firewall Services Module Crafted ICMP Message > Vulnerability > > Advisory ID: cisco-sa-20090819-fwsm > > http://www.cisco.com/warp/public/707/cisco-sa-20090819-fwsm.shtml > > Revision 1.0 > > For Public Release 2009 August 19 1600 UTC (GMT) > > Summary > ======= > > A vulnerability exists in the Cisco Firewall Services Module (FWSM) > for > the Catalyst 6500 Series Switches and Cisco 7600 Series Routers. The > vulnerability may cause the FWSM to stop forwarding traffic and may be > triggered while processing multiple, crafted ICMP messages. > > There are no known instances of intentional exploitation of this > vulnerability. However, Cisco has observed data streams that appear to > trigger this vulnerability unintentionally. > > Cisco has released free software updates that address this > vulnerability. > > This advisory is posted at > http://www.cisco.com/warp/public/707/cisco-sa-20090819-fwsm.shtml. > > Affected Products > ================= > > Vulnerable Products > - ------------------- > > All non-fixed 2.x, 3.x and 4.x versions of the FWSM software are > affected by this vulnerability. > > To determine the version of the FWSM software that is running, issue > the "show module" command-line interface (CLI) command from Cisco IOS > Software or Cisco Catalyst Operating System Software to identify what > modules and sub-modules are installed in the system. > > The following example shows a system with an FWSM (WS-SVC-FWM-1) > installed in slot 4. > > switch#show module > Mod Ports Card Type Model > Serial No. > --- ----- -------------------------------------- ----------------- > ----------- > 1 48 SFM-capable 48 port 10/100/1000mb RJ45 WS-X6548-GE-TX > SAxxxxxxxxx > 4 6 Firewall Module WS-SVC-FWM-1 > SAxxxxxxxxx > 5 2 Supervisor Engine 720 (Active) WS-SUP720-BASE > SAxxxxxxxxx > 6 2 Supervisor Engine 720 (Hot) WS-SUP720-BASE > SAxxxxxxxxx > > After locating the correct slot, issue the "show module <slot number>" > command to identify the software version that is running. > > switch#show module 4 > Mod Ports Card Type Model > Serial No. > --- ----- -------------------------------------- ----------------- > ----------- > 4 6 Firewall Module WS-SVC-FWM-1 > SAxxxxxxxxx > > Mod MAC addresses Hw Fw > Sw Status > --- --------------------------------- ------ ------------ > ------------ ------- > 4 0003.e4xx.xxxx to 0003.e4xx.xxxx 3.0 7.2(1) > 3.2(3) Ok > > The preceding example shows that the FWSM is running software version > 3.2(3) as indicated by the column under "Sw". > > Note: Recent versions of Cisco IOS Software will show the software > version of each module in the output from the "show module" command; > therefore, executing the "show module <slot number>" command is not > necessary. > > If a Virtual Switching System (VSS) is used to allow two physical > Cisco > Catalyst 6500 Series Switches to operate as a single logical virtual > switch, the "show module switch all" command can display the software > version of all FWSMs that belong to switch 1 and switch 2. The output > from this command will be similar to the output from the "show module > <slot number>" but will include module information for the modules in > each switch in the VSS. > > Alternatively, version information can be obtained directly from the > FWSM through the "show version" command, as shown in the following > example. > > FWSM#show version > FWSM Firewall Version 3.2(3) > > Customers who use the Cisco Adaptive Security Device Manager (ASDM) to > manage their devices can find the version of the software displayed in > the table in the login window or in the upper left corner of the ASDM > window. The version notation is similar to the following example. > > FWSM Version: 3.2(3) > > Products Confirmed Not Vulnerable > - --------------------------------- > > Other Cisco products that offer firewall services, including Cisco IOS > Software, Cisco ASA 5500 Series Adaptive Security Appliances, and > Cisco > PIX Security Appliances, are not affected by this vulnerability. > > No other Cisco products are currently known to be affected by this > vulnerability. > > Details > ======= > > The Cisco FWSM is a high-speed, integrated firewall module for > Catalyst > 6500 Series Switches and Cisco 7600 Series Routers. The FWSM offers > firewall services with stateful packet filtering and deep packet > inspection. > > A vulnerability exists in the Cisco FWSM Software that may cause > the FWSM to stop forwarding traffic between interfaces, or stop > processing traffic that is directed at the FWSM (management traffic) > after multiple, crafted ICMP messages are processed by the FWSM. Any > traffic that transits or is directed towards the FWSM is affected, > regardless of whether ICMP inspection ("inspect icmp" command under > Class configuration mode) is enabled. > > The FWSM stops processing traffic because one of the Network > Processors > (NPs) that is used by the FWSM to handle traffic may use all available > execution threads while handling a specific type of crafted ICMP > messages. This behavior limits the execution threads that are > available > to handle additional traffic. > > Administrators may be able to determine if the FWSM has been affected > by this vulnerability by issuing the "show np 2 stats" command. If > this > command produces output showing various counters and their values, as > shown in the example CLI output that follows, the FWSM has not been > affected by the vulnerability. If the command returns a single line > that > reads "ERROR: np_logger_query request for FP Stats failed", the FWSM > may > have been affected by the vulnerability. > > FWSM#show np 2 stats > - > ------------------------------------------------------------------------------- > Fast Path 64 bit Global Statistics Counters (NP-2) > > - > ------------------------------------------------------------------------------- > PKT_MNG: total packets (dot1q) rcvd : 10565937 > PKT_MNG: total packets (dot1q) sent : 4969517 > PKT_MNG: total packets (dot1q) dropped : 65502 > PKT_MNG: TCP packets received : 0 > PKT_MNG: UDP packets received : 4963509 > PKT_MNG: ICMP packets received : 0 > PKT_MNG: ARP packets received : 2 > PKT_MNG: other protocol pkts received : 0 > PKT_MNG: default (no IP/ARP) dropped : 0 > SESS_MNG: sessions created : 18 > SESS_MNG: sessions embryonic to active : 0 > [...] > > An FWSM that stops processing traffic as a result of this > vulnerability > will need to be reloaded. Administrators can reload the FWSM from the > supervisor of the Catalyst 6500 Series Switch or the Cisco 7600 Series > Router by issuing the command "hw-module module <slot # for FWSM> > reset" > (Cisco IOS Software), or "set module power up| down <module #>" (Cisco > CatOS Software). Note that unless the FWSM software is updated to a > non-vulnerable version, or crafted ICMP messages are blocked (see the > Workarounds section for details), the FWSM can still be subject to > exploitation (intentional or otherwise) after a reload. > > If an FWSM that is configured for failover operation encounters this > issue, the active FWSM may not properly fail over to the standby FWSM. > > IPv6 (in particular ICMPv6) cannot trigger this vulnerability. > > This issue is documented in Cisco Bug ID CSCsz97207 and has been > assigned Common Vulnerabilities and Exposures (CVE) ID CVE-2009-0638. > > Vulnerability Scoring Details > +---------------------------- > > Cisco has provided scores for the vulnerability in this advisory based > on the Common Vulnerability Scoring System (CVSS). The CVSS scoring in > this Security Advisory is done in accordance with CVSS version 2.0. > > CVSS is a standards-based scoring method that conveys vulnerability > severity and helps determine urgency and priority of response. > > Cisco has provided a base and temporal score. Customers can then > compute environmental scores to assist in determining the impact of > the > vulnerability in individual networks. > > Cisco has provided a FAQ to answer additional questions regarding CVSS > at: > > http://www.cisco.com/web/about/security/intelligence/cvss-qandas.html > > Cisco has also provided a CVSS calculator to help compute the > environmental impact for individual networks at: > > http://intellishield.cisco.com/security/alertmanager/cvss > > > * NP 2 threads lock due to processing crafted ICMP message > (CSCsz97207) > > CVSS Base Score - 7.8 > Access Vector - Network > Access Complexity - Low > Authentication - None > Confidentiality Impact - None > Integrity Impact - None > Availability Impact - Complete > > CVSS Temporal Score - 6.4 > Exploitability - Functional > Remediation Level - Official-Fix > Report Confidence - Confirmed > > > Impact > ====== > > Successful exploitation of the vulnerability may cause the FWSM to > stop forwarding traffic between interfaces (transit traffic), and stop > processing traffic directed at the FWSM (management traffic). If the > FWSM is configured for failover operation, the active FWSM may not > fail > over to the standby FWSM. > > Software Versions and Fixes > =========================== > > When considering software upgrades, also consult > http://www.cisco.com/go/psirt and any subsequent advisories to > determine > exposure and a complete upgrade solution. > > In all cases, customers should exercise caution to be certain the > devices to be upgraded contain sufficient memory and that current > hardware and software configurations will continue to be supported > properly by the new release. If the information is not clear, contact > the Cisco Technical Assistance Center (TAC) or your contracted > maintenance provider for assistance. > > Each row of the FWSM software table below describes a major FWSM > software train and the earliest possible release within that train > that > contains the fix (the "First Fixed Release") and the anticipated > date of > availability (if not currently available) in the "First Fixed Release" > column. A device running a release that is earlier than the release in > a specific column (less than the First Fixed Release) is known to be > vulnerable. The release should be upgraded at least to the indicated > release or a later version (greater than or equal to the First Fixed > Release label). > > +---------------------------------------+ > | Major | First Fixed Release | > | Release | | > |------------+--------------------------| > | 2.x | Vulnerable; migrate to | > | | 3.x or 4.x | > |------------+--------------------------| > | 3.1 | 3.1(16) | > |------------+--------------------------| > | 3.2 | 3.2(13) | > |------------+--------------------------| > | 4.0 | 4.0(6) | > +---------------------------------------+ > > Fixed FWSM software can be downloaded from the Software Center on > cisco.com by visiting http://www.cisco.com/public/sw-center/ > index.shtml > and navigating to "Security" > "Cisco Catalyst 6500 Series Firewall > Services Module" > "Firewall Services Module (FWSM) Software". > > Workarounds > =========== > > There are no workarounds for this vulnerability. Access control lists > (ACLs) that are deployed on the FWSM itself to block through-the- > device > or to-the-device ICMP messages are not effective to prevent this > vulnerability. However, blocking unnecessary ICMP messages on > screening > devices or on devices in the path to the FWSM will prevent the FWSM > from triggering the vulnerability. For example, the following ACL, > when deployed on a Cisco IOS device in front of the FWSM, will prevent > crafted ICMP messages from reaching the FWSM, and thus protect the > FWSM > from triggering the vulnerability: > > access-list 101 permit icmp any any echo > access-list 101 permit icmp any any echo-reply > access-list 101 permit icmp any any traceroute > access-list 101 permit icmp any any packet-too-big > access-list 101 permit icmp any any time-exceeded > access-list 101 permit icmp any any host-unreachable > access-list 101 permit icmp any any unreachable > access-list 101 deny icmp any any > access-list 101 permit ip any any > > This sample ACL is allowing certain ICMP messages that are vital for > network troubleshooting and for proper operation of the network. It is > safe to allow any other ICMP messages for which the Cisco IOS Software > "access-list" command has named ICMP type keywords. ACLs like the one > in the preceding example may also be deployed on non-Cisco IOS > devices, > such as the Cisco PIX and ASA security appliances, although the ACL > syntax on non-Cisco IOS devices may not support all the named ICMP > type > keywords that the Cisco IOS ACL syntax supports. However, on non-Cisco > IOS devices, it is safe to permit all ICMP messages for which there > are > named ICMP type keywords in the ACL syntax. > > As mentioned in the Details section, if the FWSM has stopped > processing > traffic due to this vulnerability, the FWSM will require a reload. > Administrators can reload the FWSM by logging in to the supervisor > of the Catalyst 6500 Series Switch or the Cisco 7600 Series router > and issuing the "hw-module module <slot # for FWSM> reset" (Cisco > IOS Software), or "set module power up|down <module #>" (Cisco CatOS > Software) commands. > > Additional mitigations that can be deployed on Cisco devices within > the > network are available in the Cisco Applied Mitigation Bulletin > companion > document for this advisory, which is available at the following link: > > http://www.cisco.com/warp/public/707/cisco-amb-20090819-fwsm.shtml. > > Obtaining Fixed Software > ======================== > > Cisco has released free software updates that address this > vulnerability. Prior to deploying software, customers should consult > their maintenance provider or check the software for feature set > compatibility and known issues specific to their environment. > > Customers may only install and expect support for the feature > sets they have purchased. By installing, downloading, accessing > or otherwise using such software upgrades, customers agree to be > bound by the terms of Cisco's software license terms found at > http://www.cisco.com/en/US/docs/general/warranty/English/EU1KEN_.html, > or as otherwise set forth at Cisco.com Downloads at > http://www.cisco.com/public/sw-center/sw-usingswc.shtml. > > Do not contact psirt(a)cisco.com or security-alert(a)cisco.com for > software > upgrades. > > Customers with Service Contracts > - -------------------------------- > > Customers with contracts should obtain upgraded software through their > regular update channels. For most customers, this means that upgrades > should be obtained through the Software Center on Cisco's worldwide > website at http://www.cisco.com. > > Customers using Third Party Support Organizations > - ------------------------------------------------- > > Customers whose Cisco products are provided or maintained through > prior > or existing agreements with third-party support organizations, such > as Cisco Partners, authorized resellers, or service providers should > contact that support organization for guidance and assistance with the > appropriate course of action in regards to this advisory. > > The effectiveness of any workaround or fix is dependent on specific > customer situations, such as product mix, network topology, traffic > behavior, and organizational mission. Due to the variety of affected > products and releases, customers should consult with their service > provider or support organization to ensure any applied workaround or > fix > is the most appropriate for use in the intended network before it is > deployed. > > Customers without Service Contracts > - ----------------------------------- > > Customers who purchase direct from Cisco but do not hold a Cisco > service > contract, and customers who purchase through third-party vendors but > are > unsuccessful in obtaining fixed software through their point of sale > should acquire upgrades by contacting the Cisco Technical Assistance > Center (TAC). TAC contacts are as follows. > > * +1 800 553 2447 (toll free from within North America) > * +1 408 526 7209 (toll call from anywhere in the world) > * e-mail: tac(a)cisco.com > > Customers should have their product serial number available and be > prepared to give the URL of this notice as evidence of entitlement > to a > free upgrade. Free upgrades for non-contract customers must be > requested > through the TAC. > > Refer to > http://www.cisco.com/en/US/support/tsd_cisco_worldwide_contacts.html > for additional TAC contact information, including localized telephone > numbers, and instructions and e-mail addresses for use in various > languages. > > Exploitation and Public Announcements > ===================================== > > The Cisco PSIRT is not aware of any public announcements or malicious > use of the vulnerability described in this advisory, but Cisco is > aware > of customers that have encountered this vulnerability during normal > network operation. > > This vulnerability was discovered during the handling of customer > support cases. > > Status of this Notice: FINAL > ============================ > > THIS DOCUMENT IS PROVIDED ON AN "AS IS" BASIS AND DOES NOT IMPLY > ANY KIND OF GUARANTEE OR WARRANTY, INCLUDING THE WARRANTIES OF > MERCHANTABILITY OR FITNESS FOR A PARTICULAR USE. YOUR USE OF THE > INFORMATION ON THE DOCUMENT OR MATERIALS LINKED FROM THE DOCUMENT IS > AT YOUR OWN RISK. CISCO RESERVES THE RIGHT TO CHANGE OR UPDATE THIS > DOCUMENT AT ANY TIME. > > A stand-alone copy or Paraphrase of the text of this document that > omits > the distribution URL in the following section is an uncontrolled copy, > and may lack important information or contain factual errors. > > Distribution > ============ > > This advisory is posted on Cisco's worldwide website at: > > http://www.cisco.com/warp/public/707/cisco-sa-20090819-fwsm.shtml > > In addition to worldwide web posting, a text version of this notice is > clear-signed with the Cisco PSIRT PGP key and is posted to the > following > e-mail and Usenet news recipients. > > * cust-security-announce(a)cisco.com > * first-bulletins(a)lists.first.org > * bugtraq(a)securityfocus.com > * vulnwatch(a)vulnwatch.org > * cisco(a)spot.colorado.edu > * cisco-nsp(a)puck.nether.net > * full-disclosure(a)lists.grok.org.uk > * comp.dcom.sys.cisco(a)newsgate.cisco.com > > Future updates of this advisory, if any, will be placed on Cisco's > worldwide website, but may or may not be actively announced on mailing > lists or newsgroups. Users concerned about this problem are encouraged > to check the above URL for any updates. > > Revision History > ================ > > +------------------------------------------------------------+ > | Revision 1.0 | 2009-August-19 | Initial public release | > +------------------------------------------------------------+ > > Cisco Security Procedures > ========================= > > Complete information on reporting security vulnerabilities > in Cisco products, obtaining assistance with security > incidents, and registering to receive security information > from Cisco, is available on Cisco's worldwide website at > http://www.cisco.com/en/US/products/products_security_vulnerability_policy.… > . > This includes instructions for press inquiries regarding > Cisco security notices. All Cisco security advisories are available at > http://www.cisco.com/go/psirt. > > +-------------------------------------------------------------------- > Copyright 2008-2009 Cisco Systems, Inc. All rights reserved. > +-------------------------------------------------------------------- > > Updated: Aug 19, 2009 Document ID: 110460 > -----BEGIN PGP SIGNATURE----- > Version: GnuPG v1.4.9 (GNU/Linux) > > iEYEARECAAYFAkqMMFYACgkQ86n/Gc8U/uA2jACeLVA38jWbQv4AGpSCvOPVJjgR > NqUAniMoiEUkV/JIDlo1xA0ztaO6jCFR > =2Tm1 > -----END PGP SIGNATURE----- > > _______________________________________________ > Full-Disclosure - We believe in it. > Charter: http://lists.grok.org.uk/full-disclosure-charter.html > Hosted and sponsored by Secunia - http://secunia.com/

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ALTER.NET Issues in Seattle
by Gary T. Giesen 19 Aug '09

19 Aug '09

Seeing issues with Alter.net in Seattle to a Qwest DSL customer in Portland (and looks like a possible routing loop as well) from Calgary: traceroute 63.227.218.201 Type escape sequence to abort. Tracing the route to 63.227.218.201 1 gw-V4051.bb101-2420-1.cgy.akn.ca (209.90.250.33) 0 msec 0 msec 0 msec 2 maxtnt01-sdf-463.fast.net (204.92.61.209) 0 msec 0 msec 0 msec 3 125.at-6-0-0.XT2.CAL1.ALTER.NET (152.63.138.122) 0 msec 0 msec 0 msec 4 POS5-0.BR1.SEA1.ALTER.NET (152.63.105.85) 224 msec 212 msec 200 msec 5 POS5-0.BR1.SEA1.ALTER.NET (152.63.105.85) 188 msec 184 msec 192 msec 6 204.255.169.30 (204.255.169.30) 192 msec 192 msec 196 msec 7 sea-core-02.inet.qwest.net (205.171.26.85) 200 msec 204 msec 204 msec 8 por-core-01.inet.qwest.net (67.14.1.237) 208 msec 212 msec 224 msec 9 ptld-agw1.inet.qwest.net (205.171.130.26) 240 msec 232 msec 236 msec 10 ptld-dsl-gw34-10.ptld.qwest.net (207.225.86.10) 236 msec 244 msec 236 msec 11 x.x.x.x (x.x.x.x) 296 msec * 252 msec Seeing pings jump from 0 ms to 200+ ms at hop 4 (which also appears as hop 5), and is definitely *not* explained by geographical distance. Traceroute from my Toronto POP are fine: traceroute 63.227.218.201 traceroute to 63.227.218.201 (63.227.218.201), 30 hops max, 60 byte packets 1 ge0-1.cyan.akn.ca (66.135.102.132) 1.506 ms 1.498 ms 1.482 ms 2 ge-0-0-3.V4022.smalt.akn.ca (66.135.108.85) 2.198 ms 2.193 ms 2.180 ms 3 te3-5.1244.ccr02.yyz02.atlas.cogentco.com (38.112.93.49) 1.640 ms 1.634 ms 1.624 ms 4 te3-2.ccr01.ord01.atlas.cogentco.com (66.28.4.213) 16.861 ms 16.884 ms te9-8.ccr01.ord01.atlas.cogentco.com (154.54.27.241) 16.890 ms 5 154.54.29.18 (154.54.29.18) 17.594 ms 17.594 ms 17.582 ms 6 qwest.ord03.atlas.cogentco.com (154.54.10.186) 17.001 ms 16.384 ms qwest.ord03.atlas.cogentco.com (154.54.12.106) 16.435 ms 7 cer-core-01.inet.qwest.net (205.171.139.113) 16.480 ms 16.795 ms 16.802 ms 8 por-core-01.inet.qwest.net (67.14.1.237) 72.435 ms 72.472 ms 72.448 ms 9 ptld-agw1.inet.qwest.net (205.171.130.26) 72.502 ms 72.473 ms 72.473 ms 10 ptld-dsl-gw34-10.ptld.qwest.net (207.225.86.10) 72.985 ms 72.958 ms 72.626 ms 11 x.x.x.x (x.x.x.x) 134.030 ms * * Anyone else seeing the same thing? GG

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Cisco Security Advisory: Cisco Security Advisory: Cisco IOS XR Software Border Gateway Protocol Vulnerability
by Cisco Systems Product Security Incident Response Team 18 Aug '09

18 Aug '09

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Cisco Security Advisory: Cisco Security Advisory: Cisco IOS XR Software Border Gateway Protocol Vulnerability Advisory ID: cisco-sa-20090818-bgp http://www.cisco.com/warp/public/707/cisco-sa-20090818-bgp.shtml Revision 1.0 For Public Release 2009 August 18 1500 UTC (GMT) - --------------------------------------------------------------------- Summary ======= Cisco IOS XR will reset a Border Gateway Protocol (BGP) peering session when receiving a specific invalid BGP update. The vulnerability manifests when a BGP peer announces a prefix with a specific invalid attribute. On receipt of this prefix, the Cisco IOS XR device will restart the peering session by sending a notification. The peering session will flap until the sender stops sending the invalid/corrupt update. This is a different vulnerability to what was disclosed in the Cisco Security Advisory "Cisco IOS Software Border Gateway Protocol 4-Byte Autonomous System Number Vulnerabilities" disclosed on the 2009 July 29 1600 UTC at the following link: http://www.cisco.com/warp/public/707/cisco-sa-20090729-bgp.shtml Cisco is preparing to release free software maintenance upgrade (SMU) that address this vulnerability. This advisory will be updated once the SMU is available. A workaround that mitigates this vulnerability is available. This advisory is posted at http://www.cisco.com/warp/public/707/cisco-sa-20090818-bgp.shtml Affected Products ================= This vulnerability affects all Cisco IOS XR software devices after and including software release 3.4.0 configured with BGP routing. Vulnerable Products +------------------ To determine the Cisco IOS XR Software release that is running on a Cisco product, administrators can log in to the device and issue the show version command to display the system banner. The system banner confirms that the device is running Cisco IOS XR Software by displaying text similar to "Cisco IOS XR Software". The software version is displayed after the text "Cisco IOS XR Software". The following example identifies a Cisco CRS-1 that is running Cisco IOS XR Software Release 3.6.2: RP/0/RP0/CPU0:CRS#show version Tue Aug 18 14:25:17.407 AEST Cisco IOS XR Software, Version 3.6.2[00] Copyright (c) 2008 by Cisco Systems, Inc. ROM: System Bootstrap, Version 1.49(20080319:195807) [CRS-1 ROMMON], CRS uptime is 4 weeks, 4 days, 1 minute System image file is "disk0:hfr-os-mbi-3.6.2/mbihfr-rp.vm" cisco CRS-8/S (7457) processor with 4194304K bytes of memory. 7457 processor at 1197Mhz, Revision 1.2 17 Packet over SONET/SDH network interface(s) 1 DWDM controller(s) 17 SONET/SDH Port controller(s) 8 TenGigabitEthernet/IEEE 802.3 interface(s) 2 Ethernet/IEEE 802.3 interface(s) 1019k bytes of non-volatile configuration memory. 38079M bytes of hard disk. 981440k bytes of ATA PCMCIA card at disk 0 (Sector size 512 bytes). Configuration register on node 0/0/CPU0 is 0x102 Boot device on node 0/0/CPU0 is mem: !--- output truncated The following example identifies a Cisco 12404 router that is running Cisco IOS XR Software Release 3.7.1: RP/0/0/CPU0:GSR#show version Cisco IOS XR Software, Version 3.7.1[00] Copyright (c) 2008 by Cisco Systems, Inc. ROM: System Bootstrap, Version 12.0(20051020:160303) SOFTWARE Copyright (c) 1994-2005 by cisco Systems, Inc. GSR uptime is 3 weeks, 6 days, 3 hours, 20 minutes System image file is "disk0:c12k-os-mbi-3.7.1/mbiprp-rp.vm" cisco 12404/PRP (7457) processor with 2097152K bytes of memory. 7457 processor at 1266Mhz, Revision 1.2 1 Cisco 12000 Series Performance Route Processor 1 Cisco 12000 Series - Multi-Service Blade Controller 1 1 Port ISE Packet Over SONET OC-48c/STM-16 Controller (1 POS) 1 Cisco 12000 Series SPA Interface Processor-601/501/401 3 Ethernet/IEEE 802.3 interface(s) 1 SONET/SDH Port controller(s) 1 Packet over SONET/SDH network interface(s) 4 PLIM QoS controller(s) 8 FastEthernet/IEEE 802.3 interface(s) 1016k bytes of non-volatile configuration memory. 1000496k bytes of disk0: (Sector size 512 bytes). 65536k bytes of Flash internal SIMM (Sector size 256k). Configuration register on node 0/0/CPU0 is 0x2102 Boot device on node 0/0/CPU0 is disk0: !--- output truncated Additional information about Cisco IOS XR software release naming conventions is available in the "White Paper: Cisco IOS Reference Guide" at the following link: http://www.cisco.com/warp/public/620/1.html#t6 Additional information about Cisco IOS XR software time-based release model is available in the "White Paper: Guidelines for Cisco IOS XR Software" at the following link: http://www.cisco.com/en/US/prod/collateral/iosswrel/ps8803/ps5845/product_b… BGP is configured in Cisco IOS XR software with the configuration command router bgp [AS Number] or router bgp [X.Y]. The device is vulnerable if it is running affected Cisco IOS XR version and has BGP configured. The following example shows a Cisco IOS XR software device configured with BGP: RP/0/0/CPU0:GSR#show running-config | begin router bgp Building configuration... router bgp 65535 bgp router-id 192.168.0.1 address-family ipv4 unicast network 192.168.1.1/32 ! address-family vpnv4 unicast ! neighbor 192.168.2.1 remote-as 65534 update-source Loopback0 address-family ipv4 unicast ! !--- output truncated Products Confirmed Not Vulnerable +-------------------------------- The following Cisco products are confirmed not vulnerable: * Cisco IOS Software * Cisco IOS XR Software prior to release 3.4.0 * Cisco IOS XR Software not configured for BGP routing No other Cisco products are currently known to be affected by this vulnerability. Details ======= On August 17th, 2009, a widely-distributed Border Gateway Protocol (BGP) route update contained an BGP Update message with a specific invalid attribute. When the invalid BGP Update message was processed by Cisco IOS XR software, it began resetting BGP peering sessions over which the update was received. When receiving the invalid update the receiving Cisco IOS XR software device will display a log message like the following example: RP/0/RP0/CPU0:Aug 17 13:47:05.896 GMT: bgp[122]: %ROUTING-BGP-5-ADJCHANGE : neighbor 192.168.0.1 Down - BGP Notification sent: invalid or corrupt AS path The peering session will flap until the sender stops sending the invalid/corrupt prefix. This vulnerability is documented in Cisco Bug ID CSCtb42995 ( registered customers only) and has been assigned Common Vulnerabilities and Exposures (CVE) ID CVE-2009-2055. Vulnerability Scoring Details ============================= Cisco has provided scores for the vulnerability in this advisory based on the Common Vulnerability Scoring System (CVSS). The CVSS scoring in this Security Advisory is done in accordance with CVSS version 2.0. CVSS is a standards-based scoring method that conveys vulnerability severity and helps determine urgency and priority of response. Cisco has provided a base and temporal score. Customers can then compute environmental scores to assist in determining the impact of the vulnerability in individual networks. Cisco has provided an FAQ to answer additional questions regarding CVSS at http://www.cisco.com/web/about/security/intelligence/cvss-qandas.html Cisco has also provided a CVSS calculator to help compute the environmental impact for individual networks at http://intellishield.cisco.com/security/alertmanager/cvss CSCtb42995 - Cisco IOS XR Software Border Gateway Protocol Vulnerability +----------------------------------------------------- CVSS Base Score - 4.3 Access Vector - Network Access Complexity - Medium Authentication - None Confidentiality Impact - None Integrity Impact - None Availability Impact - Partial CVSS Temporal Score - 3.9 Exploitability - Functional Remediation Level - Unavailable Report Confidence - Confirmed Impact ====== Successful exploitation of the vulnerability may result in BGP peering sessions continuously being reset. This may lead to routing inconsistencies and a denial of service for those affected networks. Software Versions and Fixes =========================== When considering software upgrades, also consult http://www.cisco.com/go/psirt and any subsequent advisories to determine exposure and a complete upgrade solution. In all cases, customers should exercise caution to be certain the devices to be upgraded contain sufficient memory and that current hardware and software configurations will continue to be supported properly by the new release. If the information is not clear, contact the Cisco Technical Assistance Center (TAC) or your contracted maintenance provider for assistance. +---------------------------------------+ | Cisco IOS XR Version | SMU ID | |----------------------+----------------| | 3.2.X | Not Vulnerable | |----------------------+----------------| | 3.3.X | Not vulnerable | |----------------------+----------------| | 3.4.0 | Pending | |----------------------+----------------| | 3.4.1 | Pending | |----------------------+----------------| | 3.4.2 | Pending | |----------------------+----------------| | 3.4.3 | Pending | |----------------------+----------------| | 3.5.2 | Pending | |----------------------+----------------| | 3.5.3 | Pending | |----------------------+----------------| | 3.5.4 | Pending | |----------------------+----------------| | 3.6.0 | Pending | |----------------------+----------------| | 3.6.1 | Pending | |----------------------+----------------| | 3.6.2 | Pending | |----------------------+----------------| | 3.6.3 | Pending | |----------------------+----------------| | 3.7.0 | Pending | |----------------------+----------------| | 3.7.1 | Pending | |----------------------+----------------| | 3.7.2 | Pending | |----------------------+----------------| | 3.7.3 | Pending | |----------------------+----------------| | 3.8.0 | Pending | |----------------------+----------------| | 3.8.1 | Pending | +---------------------------------------+ Workarounds =========== There are no workarounds on the affected device itself. Co-ordination is required with the peering neighbor support staff to filter the invalid update on their outbound path. The following procedure explains how to help mitigate this vulnerability: Using the peer IP address in the log message that was generated when the Cisco IOS XR software device received the invalid update; capture the notification message hex dump from the CLI command show bgp neighbor and contact the Cisco TAC whom can assist with a decode. Details on how to contact Cisco TAC are contained within the section "Obtaining Fixed Software" of this advisory. The following example show an example generated log message when receiving the invalid update, and the details to be captured to be sent to the Cisco TAC for decoding: Log message generated when receiving invalid update: RP/0/RP0/CPU0:Aug 17 13:47:05.896 GMT: bgp[122]: %ROUTING-BGP-5-ADJCHANGE : neighbor 192.168.0.1 Down - BGP Notification sent: invalid or corrupt AS path Information to capture for decoding by the Cisco TAC, is the output from show bgp neighbors [ip address of neighbor from above log message]. RP/0/RP0/CPU0:CRS#show bgp neighbors 192.168.0.1 <capture output and provide to Cisco TAC> Working with Cisco TAC, the decode of the above will display the AS path in a manner illustrated below. ATTRIBUTE NAME: AS_PATH AS_PATH: Type 2 is AS_SEQUENCE AS_PATH: Segment Length is 4 (0x04) segments long AS_PATH: 65533 65532 65531 65531 Working cooperatively with your peering partner, request that they filter outbound prefix advertisements from the identified source AS (in this example 65531) for your peering session. The filters configuration methods will vary depending on the routing device operating system used. For Cisco IOS XR the filters will be applied using Routing Policy Language (RPL) policies or with Cisco IOS software via applying route-maps that deny advertisements matching that AS in their AS-PATH. Once these policies are applied, the peering session will be re-established. For further information on Cisco IOS XR RPL consult the document "Implementing Routing Policy on Cisco IOS XR Software" at the following link: http://www.cisco.com/en/US/docs/ios_xr_sw/iosxr_r3.0/routing/configuration/… For further information on Cisco IOS route maps with BGP, consult the document "Cisco IOS BGP Configuration Guide, Release 12.4T" at the following link: http://www.cisco.com/en/US/docs/ios/12_2sr/12_2srb/feature/guide/tbgp_c.html Obtaining Fixed Software ======================== Cisco will be releasing free software updates that address this vulnerability. Prior to deploying software, customers should consult their maintenance provider or check the software for feature set compatibility and known issues specific to their environment. Customers may only install and expect support for the feature sets they have purchased. By installing, downloading, accessing or otherwise using such software upgrades, customers agree to be bound by the terms of Cisco's software license terms found at http://www.cisco.com/en/US/docs/general/warranty/English/EU1KEN_.html or as otherwise set forth at Cisco.com Downloads at http://www.cisco.com/public/sw-center/sw-usingswc.shtml Do not contact psirt(a)cisco.com or security-alert(a)cisco.com for software upgrades. Customers with Service Contracts +------------------------------- Customers with contracts should obtain upgraded software through their regular update channels. For most customers, this means that upgrades should be obtained through the Software Center on Cisco's worldwide website at http://www.cisco.com. Customers using Third Party Support Organizations +------------------------------------------------ Customers whose Cisco products are provided or maintained through prior or existing agreements with third-party support organizations, such as Cisco Partners, authorized resellers, or service providers should contact that support organization for guidance and assistance with the appropriate course of action in regards to this advisory. The effectiveness of any workaround or fix is dependent on specific customer situations, such as product mix, network topology, traffic behavior, and organizational mission. Due to the variety of affected products and releases, customers should consult with their service provider or support organization to ensure any applied workaround or fix is the most appropriate for use in the intended network before it is deployed. Customers without Service Contracts +---------------------------------- Customers who purchase direct from Cisco but do not hold a Cisco service contract, and customers who purchase through third-party vendors but are unsuccessful in obtaining fixed software through their point of sale should acquire upgrades by contacting the Cisco Technical Assistance Center (TAC). TAC contacts are as follows. * +1 800 553 2447 (toll free from within North America) * +1 408 526 7209 (toll call from anywhere in the world) * e-mail: tac(a)cisco.com Customers should have their product serial number available and be prepared to give the URL of this notice as evidence of entitlement to a free upgrade. Free upgrades for non-contract customers must be requested through the TAC. Refer to http://www.cisco.com/en/US/support/tsd_cisco_worldwide_contacts.html for additional TAC contact information, including localized telephone numbers, and instructions and e-mail addresses for use in various languages. Exploitation and Public Announcements ===================================== On August 17, 2009 around 16:30-17:00 UTC several ISP's began experiencing connectivity issues as BGP sessions were being repeatedly reset. Cisco TAC was engaged with a number of customers all seeing similar issues. Stability came a few hours afterward as workarounds were applied. At this time, it is not believed that the connectivity issues were the result of malicious activity. Status of this Notice: INTERIM ============================== THIS DOCUMENT IS PROVIDED ON AN "AS IS" BASIS AND DOES NOT IMPLY ANY KIND OF GUARANTEE OR WARRANTY, INCLUDING THE WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR USE. YOUR USE OF THE INFORMATION ON THE DOCUMENT OR MATERIALS LINKED FROM THE DOCUMENT IS AT YOUR OWN RISK. CISCO RESERVES THE RIGHT TO CHANGE OR UPDATE THIS DOCUMENT AT ANY TIME. CISCO EXPECTS TO UPDATE THIS DOCUMENT AS NEW INFORMATION BECOMES AVAILABLE. A stand-alone copy or Paraphrase of the text of this document that omits the distribution URL in the following section is an uncontrolled copy, and may lack important information or contain factual errors. Distribution ============ This advisory is posted on Cisco's worldwide website at : http://www.cisco.com/warp/public/707/cisco-sa-20090818-bgp.shtml In addition to worldwide web posting, a text version of this notice is clear-signed with the Cisco PSIRT PGP key and is posted to the following e-mail and Usenet news recipients. * cust-security-announce(a)cisco.com * first-bulletins(a)lists.first.org * bugtraq(a)securityfocus.com * vulnwatch(a)vulnwatch.org * cisco(a)spot.colorado.edu * cisco-nsp(a)puck.nether.net * full-disclosure(a)lists.grok.org.uk * comp.dcom.sys.cisco(a)newsgate.cisco.com Future updates of this advisory, if any, will be placed on Cisco's worldwide website, but may or may not be actively announced on mailing lists or newsgroups. Users concerned about this problem are encouraged to check the above URL for any updates. Revision History ================ +---------------------------------------+ | Revision | | Initial | | 1.0 | 2009-August-18 | public | | | | release. | +---------------------------------------+ Cisco Security Procedures ========================= Complete information on reporting security vulnerabilities in Cisco products, obtaining assistance with security incidents, and registering to receive security information from Cisco, is available on Cisco's worldwide website at http://www.cisco.com/en/US/products/products_security_vulnerability_policy.… This includes instructions for press inquiries regarding Cisco security notices. All Cisco security advisories are available at http://www.cisco.com/go/psirt - --------------------------------------------------------------------- -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.5 (Darwin) iD8DBQFKitOJ86n/Gc8U/uARAlpUAJ95EA/XmiFntl4XuXpKTpqeIt5q8gCfdOPV /OmnNTdlD9lueFh99gS6NDM= =dejJ -----END PGP SIGNATURE-----

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East Africa Fibre Connectivity- Heads up
by Raymond Macharia 18 Aug '09

18 Aug '09

Hello all,in the last two weeks or so providers in East Africa, particularly in Kenya where I am, have been moving from Satellite to Fibre for the internet Back bone connectivity. From where I am I have seen an upsurge of about 100Mbps in the last two days from my users. It would be interesting to know if anyone out there has seen an increase in traffic from this region and by how much. There is more to come as providers are cutting prices and adding bandwidth to their networks. Best Regards Raymond Macharia

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bits/hz/second: we're barely more efficient than the telegraph (Re: TransAtlantic 40 Gig Waves
by Anton Kapela 17 Aug '09

17 Aug '09

I'll comment on both: On Mon, Aug 17, 2009 at 12:14 PM, Rod Beck<Rod.Beck(a)hiberniaatlantic.com> wrote: > Rod, do you know if the 40G waves increased the spectrum efficiency of > your fiber? On land systems they pretty much break even, i.e. you can [rod beck replies] > The enabling technology is based on advanced encoding techniques allowing a greater rate of symbol transfer." Looking back in Google and other IEEE papers, the previous 20 years of interfacing our abstract "bits" to the real world via photons hasn't been met with terribly high efficiencies, though we certainly have seen both great progress in the transmitter (who could have imagined a VCSEL in 1985?) and receiver technology, and of course a significant improvement in usable bits/sec. I can only wonder what the curve of optical spectral efficiency we achieve over the next decades will resemble. Perhaps we'll have to wait for a "Shannon of Optics" to stand up (or quit their day job at whatever modern-day version of $bell_labs they're stuck working for) and point out something obvious we're missing. A bit of sobering reality I often consider is we waited roughly a century to progress from where Marconi began to the present day, where we have cheap radios doing 12 bits/hz/sec costing about $20k (a pair). Clearly a key difference is that people are paying (allot, propotionately) to communicate $stuff and folks value networks more than they did previously - so we're not in the same position folks were pre-1900's, struggling to find a market for their crazy wires across the sea. For the experts out there: how long are we going to wait for something more efficient than morse code over twisted pairs? -Tk

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Re: Anyone else seeing "(invalid or corrupt AS path) 3 bytes E01100" ?
by deleskie＠gmail.com 17 Aug '09

17 Aug '09

I'd have to _assume_ that a lot of those impacted don't have a maint contract with their router vendor of choice and therefore don't have an easy path to upgrade. -jim ------Original Message------ From: Jared Mauch To: randal k Cc: nanog(a)nanog.org Subject: Re: Anyone else seeing "(invalid or corrupt AS path) 3 bytes E01100" ? Sent: Aug 17, 2009 7:40 PM On Aug 17, 2009, at 5:37 PM, randal k wrote: > Yep, we started seeing this right around 12:20pm MST. We saw it from a > customer's rapidly-flapping BGP peer. We told them to configure bgp > maxas-limit, but apparently CRS1s don't have that command. > > Anybody have a handy route-map that will deny anything with a as-path > longer than say 15-20? ;-) Is there some significant barrier to people getting recent code on the devices that is not impacted by this and the other fun bgp 'attacks' that can happen? We usually see customers drop bgp sessions all over, making me wonder ... if you're not able to upgrade, what is the issue? Just that most people don't see these as an attack against their infrastructure? That people are unwilling to upgrade code unless it has a long-term impact to their operations? An outage once every few months is OK? - Jared Sent from my BlackBerry device on the Rogers Wireless Network

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