BLT001
@attbi.com
| [Networking] No route to ATTBI neighbor
An interesting issue here. Both my psudo-neighbor (5 miles away) and I can access the internet just fine with low latency but neither of us can communicate with each other. Both of us are on the ATTBI network.
(From my box to his)
C:\>tracert 12.224.209.98
Tracing route to 12-224-209-98.client.attbi.com [12.224.209.98]
over a maximum of 30 hops:
1 25 ms 54 ms 10 ms 10.138.160.1
2 * * * Request timed out.
3 * * * Request timed out.
The box I am on does not filter out ICMP at all and neither does his box. Other protocols such as FTP do not work between us either as there is no working route.
Is it possibly a routing issue within the headend? I've never had an issue reaching another client on the ATTBI network before unless there was a massive outage.
Any and all help is appreciated. |
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BLT001
@attbi.com | Oh yeah, forgot to mention Im in the Beaverton, OR area.
Cheerz. |
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xxxxxxx
@attbi.com | The router thinks that your neighbor is in the local subnet (defined by the netmask in the address that you get from attbi). However, the truth is that the packet must go through the gateway as every other packet going to the internet. |
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Kip patterson
Premium
join:2000-10-23
Columbus, OH
| reply to BLT001
Three possibilities:
1) There is a bug is some earlier versions of Cisco software that causes this.
2) An intentional configuration by your ISP
3) An incorrect subnet as mentioned above.
From a remote traceroute server (use Google to find one) do a traceroute to his IP and yours. Check to see if the last router, which is the CMTS, is the same. Check his IP address against yours and against both subnets to see if they are in the same subnet, or post them here, omitting the last set of digits and someone will help.
Kip |
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nothere
@159.247.x.x | reply to BLT001
2) An intentional configuration by your ISP
This be the reason. Att blocks local communications. Try using a proxy. |
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AuroraMike
Time To Blow Some Bubbles
Premium
join:2002-01-06
Aurora, CO | reply to BLT001
AT&T blocks file sharing and NETBUI, but they don't block pings. Sounds more like a router or configuration problem.
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porta
@attbi.com
| Whether intentional or not, ATT in Beaverton feeds you information via DHCP that effectively make it impossible to talk to your neighbors. The only way to make it work is to change the netmask or install a static route to both your neighbor's and your router. |
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porta
@attbi.com
| Let me more specific. This is my route table after dhcp:
12.231.222.0 * 255.255.252.0 U 0 0 0 eth1
default 12-231-222-1.cl 0.0.0.0 UG 0 0 0 eth1
Essentially, it tells my router to broadcast whenever it wants to talk to anybody in the local subnet. The ATT headend does not broadcast anything.
I have to add an explicit route entry, with precedence over the DHCP supplied route, to make it work.
12.231.222.0 12-231-222-1.cl 255.255.252.0 UG 0 0 0 eth1 |
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