Need help from those who have Sprint, UUNET, or Verio Internet circuits at work.

[Cooky]

If you have Sprint, UUNET/Verizon/MCI, or Verio Internet circuits at work, could you please post the output of "show ip bgp 161.38.221.0" (assuming Cisco) from your Internet edge routers?

We're trying to have Qwest prepend their ASN (209) once towards the above three peers, but it doesn't seem to be working.
I already talked to Qwest NOC, but they weren't really helpful.

I wanted to confirm the end customers are seeing the same AS path as what I'm seeing from some of the route servers.

thanks.

 

[jlazzaro]

which community string are you using? Verizon DS3 in Munich...

BGP routing table entry for 161.38.221.0/24, version 5854253
Paths: (1 available, best #1, table Default-IP-Routing-Table)
Advertised to update-groups:
1
702 701 2828 33039, (received & used)
149.227.0.14 from 149.227.0.14 (149.227.0.14)
Origin incomplete, localpref 100, valid, external, best
Community: 46007292

 

[Cooky]

Thanks for the prompt response!

It looks like the prefix you're receiving is via XO (2828), then Verizon.
I was hoping to see something like 702 701 209 209 33039.

We have two GigE pipes through Qwest & XO on our user internet side.
Due to its larger footprint, we want Qwest to prepend its ASN towards a few of its peers, namely Sprint, UUNET, and Verio.
So we configured the following on our neighbor session w/ Qwest:
set community 209:64541 209:64551 209:64581

Supposedly Qwest would prepend 209 once for their peer sessions w/ the above three carriers, but we're not seeing that w/ Verio:
2914 209 33039

So I wanted to see what others are seeing in their BGP RIB.

Based on your output, Verizon chose the route via XO instead of Qwest.
Not sure which part of the path selection process made it that way.

I guess the only way to find out is to call Verizon and ask for their show ip bgp output.
We have Verizon & ATT on our eCommerce segment, but we re-used the ASN, so the route wouldn't make it into our Verizon BGP table unless we specify "neighbor allowas-in".

 

[jlazzaro]

hmm...id send you our Sprintlink entries, but we default route w/ conditional advertisements. it doesn't seem like Verizon has any publicly available looking glass servers, and the Sprintlink one doesn't allow ip bgp commands.

Internet routing...the black art 🙂

 

[Emulex]

you guys notice how ATT&comcast are doing some really whack isht lately?

i've got GA going to DALLAS on comcast, then peering through (TATA !?@ WTF) then going back over the att.net to florida (orlando! woot).

they must be pissed at each other or have a major bgp typo to do that route.

 

[Cooky]

To be honest I don't know your network, so can't comment on how wacky it is.
What I do know is the path to your destination could be different from the path on the way back.

Forward path is determined by you, your ISP, and your ISP's upstream provider or peer's BGP tables.
There's no guarantee that they're exactly the same as the route that your destination, its ISP, and their peers will take for the return path.

 

[Cooky]

So I decided to temporarily allow our own ASN in just to confirm Qwest is prepending their ASN.
It appears they are doing it for their ATT & UUNET peerings, but just not for their Verio peering session.
I can care less about Verio, so will probably tell Qwest to close the ticket and be done w/ it.

CS-RTRI-34-232#sh ip bgp 161.38.221.0
BGP routing table entry for 161.38.221.0/24, version 645553
Paths: (2 available, best #2, table Default-IP-Routing-Table)
Flag: 0x820
Advertised to update-groups:
1
701 209 209 33039
161.38.220.5 from 161.38.220.5 (10.1.x.y)
Origin IGP, metric 0, localpref 100, valid, internal
7018 209 209 33039
12.88.26.161 from 12.88.26.161 (12.122.125.99)
Origin IGP, localpref 100, valid, external, best

===
route-views.oregon-ix.net>sh ip bgp 161.38.221.0 | inc 209
...
2914 209 33039