I'm running short on theories and options, so I thought I would see if any other ISPs have seen this problem on your network(s). If so, what was the cure? mjr -----Original Message----- The Unknown problem. Symptoms: At random times dialup, dedicated, & internal network users are unable to pass TCP traffic to off network sites. ICMP and UDP appears to be uneffected by the outage which lasts anywhere from 2 to 5 minutes. The problem appears to be wide spread with similar reports from WVNET and other ISPS. nTelos is experiencing a similar problem but we have yet to confirm it is the same. Problem has changed in it's action but remained similar enough to consider it the same problem. Effected Platforms: Windows 2000 Pro, XP Home, XP Pro, & 2003 Server. Uneffected Platforms: Unix, MacOS (?) History: During the week of 2/9/04 the call center started recieving reports of users being unable to connect to sites off the CityNet network. Sites hosted on the internal network are uneffected by the outage. Initally it was thought to be a Internet Explorer problem possably caused by the KB832894 / IE SP1 or other updates but after further investigation it was found that Mozilla users were encountering the same problem. After several days of testing it was determined that during the outage any TCP session started on any port would fail. TCP sessions started before the outage continue to work and show no ill effects from the outage. After logging connection attempts at various intervals on many machines there appears to be no sort of pattern in the outages. Most machines encounter the problem, some more than others and a few do not encounter it at all. The duration and frequency of the outage is very fluid. During an outage, we can verify that the packet does seem to leave and reenter the network: Mar 5 22:28:04 pittpa-chaswv-ds3 17083: SLOT 2:6d20h: %SEC-6-IPACCESSLOGP: list 113 permitted tcp 69.43.14.174(3376) -> 216.41.224.3(80), 1 packet Mar 5 22:28:09 pittpa-chaswv-ds3 17084: SLOT 1:6d20h: %SEC-6-IPACCESSLOGP: list 111 permitted tcp 216.41.224.3(80) -> 69.43.14.174(3376), 1 packet Mar 5 22:28:09 pittpa-chaswv-ds3 17085: SLOT 2:6d20h: %SEC-6-IPACCESSLOGP: list 113 permitted tcp 69.43.14.174(3378) -> 216.41.224.3(80), 1 packet Mar 5 22:28:09 pittpa-chaswv-ds3 17086: SLOT 1:6d20h: %SEC-6-IPACCESSLOGP: list 111 permitted tcp 216.41.224.3(80) -> 69.43.14.174(3378), 1 packet Mar 5 22:33:24 pittpa-chaswv-ds3 17089: SLOT 1:6d20h: %SEC-6-IPACCESSLOGP: list 111 permitted tcp 216.41.224.3(80) -> 69.43.14.174(3378), 7 packets Mar 5 22:33:24 pittpa-chaswv-ds3 17090: SLOT 1:6d20h: %SEC-6-IPACCESSLOGP: list 111 permitted tcp 216.41.224.3(80) -> 69.43.14.174(3376), 17 packets Mar 5 22:33:58 pittpa-chaswv-ds3 17092: SLOT 2:6d20h: %SEC-6-IPACCESSLOGP: list 113 permitted tcp 69.43.14.174(3378) -> 216.41.224.3(80), 7 packets Mar 5 22:33:58 pittpa-chaswv-ds3 17093: SLOT 2:6d20h: %SEC-6-IPACCESSLOGP: list 113 permitted tcp 69.43.14.174(3376) -> 216.41.224.3(80), 18 packets Mar 5 00:58:30 pittpa-clarwv-ds3 16062: SLOT 2:5d22h: %SEC-6-IPACCESSLOGP: list 113 permitted tcp 69.43.23.23(3183) -> 216.41.224.3(80), 1 packet Mar 5 00:58:30 pittpa-clarwv-ds3 16063: SLOT 1:5d22h: %SEC-6-IPACCESSLOGP: list 111 permitted tcp 216.41.224.3(80) -> 69.43.23.23(3183), 1 packet Mar 5 01:03:28 pittpa-clarwv-ds3 16067: SLOT 2:5d22h: %SEC-6-IPACCESSLOGP: list 113 permitted tcp 69.43.23.23(3217) -> 216.41.224.3(80), 1 packet Mar 5 01:03:28 pittpa-clarwv-ds3 16068: SLOT 1:5d22h: %SEC-6-IPACCESSLOGP: list 111 permitted tcp 216.41.224.3(80) -> 69.43.23.23(3217), 1 packet Mar 5 01:03:34 pittpa-clarwv-ds3 16069: SLOT 2:5d22h: %SEC-6-IPACCESSLOGP: list 113 permitted tcp 69.43.23.23(3228) -> 216.41.224.3(80), 1 packet Mar 5 01:03:34 pittpa-clarwv-ds3 16070: SLOT 1:5d22h: %SEC-6-IPACCESSLOGP: list 111 permitted tcp 216.41.224.3(80) -> 69.43.23.23(3228), 1 packet Mar 5 01:03:39 pittpa-clarwv-ds3 16072: SLOT 2:5d22h: %SEC-6-IPACCESSLOGP: list 113 permitted tcp 69.43.23.23(3239) -> 216.41.224.3(80), 1 packet Mar 5 01:03:47 pittpa-clarwv-ds3 16073: SLOT 2:5d22h: %SEC-6-IPACCESSLOGP: list 113 permitted tcp 69.43.23.23(3183) -> 216.41.224.3(80), 74 packets Mar 5 01:04:13 pittpa-clarwv-ds3 16075: SLOT 1:5d22h: %SEC-6-IPACCESSLOGP: list 111 permitted tcp 216.41.224.3(80) -> 69.43.23.23(3183), 72 packets Mar 5 01:08:46 pittpa-clarwv-ds3 16078: SLOT 2:5d22h: %SEC-6-IPACCESSLOGP: list 113 permitted tcp 69.43.23.23(3218) -> 216.41.224.3(80), 4 packets Mar 5 01:08:46 pittpa-clarwv-ds3 16079: SLOT 2:5d22h: %SEC-6-IPACCESSLOGP: list 113 permitted tcp 69.43.23.23(3217) -> 216.41.224.3(80), 3 packets Mar 5 01:08:46 pittpa-clarwv-ds3 16080: SLOT 2:5d22h: %SEC-6-IPACCESSLOGP: list 113 permitted tcp 69.43.23.23(3221) -> 216.41.224.3(80), 19 packets Mar 5 01:08:46 pittpa-clarwv-ds3 16081: SLOT 2:5d22h: %SEC-6-IPACCESSLOGP: list 113 permitted tcp 69.43.23.23(3228) -> 216.41.224.3(80), 5 packets Mar 5 01:08:46 pittpa-clarwv-ds3 16082: SLOT 2:5d22h: %SEC-6-IPACCESSLOGP: list 113 permitted tcp 69.43.23.23(3229) -> 216.41.224.3(80), 6 packets Mar 5 01:08:46 pittpa-clarwv-ds3 16083: SLOT 2:5d22h: %SEC-6-IPACCESSLOGP: list 113 permitted tcp 69.43.23.23(3236) -> 216.41.224.3(80), 9 packets Mar 5 01:08:47 pittpa-clarwv-ds3 16084: SLOT 2:5d22h: %SEC-6-IPACCESSLOGP: list 113 permitted tcp 69.43.23.23(3233) -> 216.41.224.3(80), 12 packets Mar 5 01:08:47 pittpa-clarwv-ds3 16085: SLOT 2:5d22h: %SEC-6-IPACCESSLOGP: list 113 permitted tcp 69.43.23.23(3239) -> 216.41.224.3(80), 21 packets Mar 5 01:09:12 pittpa-clarwv-ds3 16087: SLOT 1:5d22h: %SEC-6-IPACCESSLOGP: list 111 permitted tcp 216.41.224.3(80) -> 69.43.23.23(3239), 19 packets Mar 5 01:09:12 pittpa-clarwv-ds3 16088: SLOT 1:5d22h: %SEC-6-IPACCESSLOGP: list 111 permitted tcp 216.41.224.3(80) -> 69.43.23.23(3228), 4 packets Mar 5 01:09:12 pittpa-clarwv-ds3 16089: SLOT 1:5d22h: %SEC-6-IPACCESSLOGP: list 111 permitted tcp 216.41.224.3(80) -> 69.43.23.23(3217), 2 packets Mar 5 01:09:12 pittpa-clarwv-ds3 16091: SLOT 1:5d22h: %SEC-6-IPACCESSLOGP: list 111 permitted tcp 216.41.224.3(80) -> 69.43.23.23(3218), 3 packets Mar 5 01:09:13 pittpa-clarwv-ds3 16092: SLOT 1:5d22h: %SEC-6-IPACCESSLOGP: list 111 permitted tcp 216.41.224.3(80) -> 69.43.23.23(3221), 17 packets Mar 5 01:09:13 pittpa-clarwv-ds3 16093: SLOT 1:5d22h: %SEC-6-IPACCESSLOGP: list 111 permitted tcp 216.41.224.3(80) -> 69.43.23.23(3229), 5 packets Mar 5 01:09:13 pittpa-clarwv-ds3 16094: SLOT 1:5d22h: %SEC-6-IPACCESSLOGP: list 111 permitted tcp 216.41.224.3(80) -> 69.43.23.23(3236), 7 packets Mar 5 01:09:13 pittpa-clarwv-ds3 16096: SLOT 1:5d22h: %SEC-6-IPACCESSLOGP: list 111 permitted tcp 216.41.224.3(80) -> 69.43.23.23(3233), 9 packets Network analysis showed significant amounts of spoofed multicast traffic and odd arp traffic. 10:17:16.416222 IP 192.168.1.1.1900 > 239.255.255.250.1900: udp 278 10:17:16.421886 IP 192.168.1.1.1900 > 239.255.255.250.1900: udp 334 10:17:16.423873 IP 192.168.1.1.1900 > 239.255.255.250.1900: udp 262 10:17:16.426948 IP 192.168.1.1.1900 > 239.255.255.250.1900: udp 254 10:17:16.432095 IP 192.168.1.1.1900 > 239.255.255.250.1900: udp 298 10:17:16.435921 IP 192.168.1.1.1900 > 239.255.255.250.1900: udp 274 10:17:16.439959 IP 192.168.1.1.1900 > 239.255.255.250.1900: udp 328 10:17:16.445317 IP 192.168.1.1.1900 > 239.255.255.250.1900: udp 326 10:17:16.449688 IP 192.168.1.1.1900 > 239.255.255.250.1900: udp 330 10:17:16.463537 IP 192.168.1.1.1900 > 239.255.255.250.1900: udp 322 Steps were taken to elminiate the spoofed traffic on the routers and access servers in the form of ACLs and filter lists. Neither have eliminiated the problem... but to what extent they might have helped has yet to be determined. The problem is still occuring, for some users the duration of the outage seems to have shortened other users notice no difference. It is not yet known if the filtering on the routers and access servers or the conversion to the 10.x.x.x network has made any difference. We should have a better idea in the upcoming days. What Doesn't help: Removing windows updates. Turning off XP firewall. Searching for malware. (SpyBot-SD, Adaware) Virus scanning (Various softwares) Specifying dns servers. Reinstalling windows.