January 2012 - Test - lists.nanog.org

Redundant multicast routing
by Mark Smith 03 Jan '12

03 Jan '12

Hi What's your recipe to implement redundant multicast (stub) routing? Let's think about the simplest scenario. We have 2 routers, R1 and R2 and 3 ip networks. All 3 networks are directly connected to both routers and the routers are performing unicast routing between networks using VRRP as the redundancy protocol. Let's disregard L2 redundancy here and assume it works. Same goes with igmp snoop. net1: 192.168.1.0/24, VRRP .254, R1 .1, R2 .2 net2: 192.168.2.0/24, VRRP .254, R1 .1, R2 .2 net3: 192.168.3.0/24, VRRP .254, R1 .1, R2 .2 Say multicast source is in net1 and receiver in net2. If I did not need redundancy in multicast, I would just configure all interfaces on R1 as pim passive and it would (probably) work. But if I want the multicast routing to be redundant, what should I do? If I add the R2 interfaces as pim passive, the multicast is forwarded to net2 (and net3) twice because R1 and R2 do not know about each other. I tested this. If I configure all R1 and R2 interfaces as pim dense, the destination receives multicast fine, but it is flooded between R1 and R3 2 or 3 times (because pim dense floods the multicast to all pim neighbors and R1 and R2 are pim neighbors in all 2 networks). So, core links are unnecessarily consumed. I tested this, too. One choice could be to use pim sparse and configure R1 and R2 to be anycast RPs using loopback interface and configure MSDP peering between them. But given the simplicity of the topology, this seems unnecessarily complex configuration. I have not tested this yet. Maybe MVR could be solution but I think it will cause stream multiplication too. I have not tested MVR yet either. I would like to keep the recipe as vendor agnostic as possible. Thanks for help :)

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HotICE 2012 -- paper registration deadline Friday Jan 6, 2012
by Ramana Kompella 03 Jan '12

03 Jan '12

[Apologies if you received multiple copies of this CFP] The 2nd USENIX Workshop on Hot Topics in Management of Internet, Cloud, and Enterprise Networks and Services (Hot-ICE '12) Program Co-Chairs invite you to contribute to the refereed papers. The Hot-ICE workshop seeks to bring together researchers and practitioners working on network and service management in the Internet, cloud, and enterprise domains. Paper registration is due *January 6, 2012*, by 11:59 p.m. PST (i.e. Friday !). Complete paper submissions are due January 13, 2012, by 11:59 p.m. PST. For more information and the submission guidelines, please visit http://www.usenix.org/hotice12/cfpa. Hot-ICE '12 will be held on April 24, 2012, in San Jose, CA, and will be co-located with NSDI '12: http://www.usenix.org/nsdi12 On behalf of the Hot-ICE '12 Program Committee, Olivier Bonaventure, Universite catholique de Louvain Ramana Kompella, Purdue University

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next-best-transport! down with ethernet!
by Christopher Morrow 03 Jan '12

03 Jan '12

(you forgot to change subj:) On Thu, Dec 29, 2011 at 7:59 AM, Cameron Byrne <cb.list6(a)gmail.com> wrote: > Next topic, ethernet is too chaotic and inefficient to deploy and support > mission critical applications in LAN or WAN or data center. yes, let's get something with say fixed sized packets, ability to have predictable jitter and also, for fun, no more STP! Ethernet is too complex, maybe something simpler? I hear there's this new tech 'ATM'? it seems to fit the bill! :) (Happy new year almost)

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L3 consequences of WLAN offload in cellular networks (was - endless DHCPv6 thread)
by Alexander Harrowell 02 Jan '12

02 Jan '12

In the DHCP v6 thread, there was some discussion of mobility and its IP layer consequences. As various people pointed out, cellular networks basically handle this in the RAN (Radio Access Network) and therefore at layer 2, transparently (well, as much as things ever are) for IP purposes. It therefore shouldn't be a problem. However, as one contributor pointed out, more and more cellular operators are migrating traffic onto WLAN for various reasons, notably: 1) Spectrum - it's unlicensed, i.e. free 2) Capex - the equipment is cheaper 3) Capacity - it's a cheap way of providing high speed 4) Signalling load - it gets rid of the signalling traffic associated with detaching and attaching devices from the core network. This is especially important in view of some smartphones' behaviour. Of course much of the signalling is associated with the Mobility Management features, and getting rid of it by punting everything to WLAN implies that you lose the benefits of this. That suggests that if you're going to do this on a big scale you need to implement Mobile IP or else keep backhauling traffic from the WLAN access points to the cellular core network (GAN/Iu interface), which has obvious effects on the economics of the whole idea. Alternatively, you can work on the assumption that the WLAN is solely for nomadic use rather than true mobility, but a lot of devices will prefer the WLAN whenever possible. Thoughts/experiences? -- The only thing worse than e-mail disclaimers...is people who send e-mail to lists complaining about them

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Ethernet From China to Singapor or Hong Kong ?
by Olivier CALVANO 02 Jan '12

02 Jan '12

Hi anyone have contact of a operator (CHina Telecom ? CPC ?) that can provide L2 Link from China to Singapor or if not direct link, China to Hong Kong. Thanks Olivier

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Hotmail / MSN blacklisting policies.
by James Smallacombe 02 Jan '12

02 Jan '12

The IP address of our mail server was recently blacklisted by MSN/Hotmail. When I went through their steps for delisting, it was denied based on "reputation". AFAIK, we have not had a spam problem for several months. When we did it was due to a few accounts having been successfully phished. Since then our customers have been far more savvy and I have not seen the problem. I manually delisted us from all the known BLs back then and all has been ok. A current multi DNSBL lookup only shows 3 out of a couple hundred BLs listing us. You may be familiar with the ones that did (blackholes.five-ten-sg.com for example). No major, reputable, widely used DNSBL lists the IP. I have been doing this for 16 years. It has always been SOP to provide an offending email, with full headers to the complaint recipient, if not in advance of such blacklisting, then at least upon request. They sure require it of me when I report abuse of their servers. They flat out refuse to do this, claiming they have no access to this. I had this same issue with Cloudmark's BL a couple of months ago (which Comcast and other major providers use), so I suspect this is some kind of outsourced blacklist that does a poor job of updating their listings or one of my regular customers is sending out emails that are being incorrectly reported as spam. I have seen the latter happen several times with other servers I've worked with that auto generate legitimate emails of reports that customers pay for, but aggressive filters such as AOL's auto-report as spam (to be fair, AOL is excellent at resolving these). We do have SPF records for our main domains, but no DKIM or other whitelisting/authentication mechanisms. Is this sort of thing going to be widely required?

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Re: Does anybody out there use Authentication Header (AH)?
by David Barak 01 Jan '12

01 Jan '12

It can be used to prevent NAT on an intermediate path, which can be useful under certain circumstances. I have seen it in the wild, both in Internet and private networking contexts. David Barak

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