15 Mar

BSNL routing tables and upstreams

Just was looking at routing tables of BSNL. They have a significant address space in /10 – 117.192.0.0/10. Overall this /10 address space is divided into /18 and /20 subnets.

 

Let’s pick two of such subnets and observe routing tables from route-views:

  1. 117.192.0.0/18
  2. 117.192.0.0/20 

 

Routing table for 117.192.0.0/18

* 117.192.0.0/18 193.0.0.56 0 3333 3356 6453 4755 9829 9829 9829 i
* 194.85.102.33 0 3277 3216 6453 4755 9829 9829 9829 i
* 194.85.40.15 0 3267 174 6453 4755 9829 9829 9829 i
* 129.250.0.11 6 0 2914 6453 6453 4755 9829 9829 9829 i
* 128.223.253.10 0 3582 3701 3356 6453 4755 9829 9829 9829 i
* 4.69.184.193 0 0 3356 6453 4755 9829 9829 9829 i
* 209.124.176.223 0 101 101 3356 6453 4755 9829 9829 9829 i
* 69.31.111.244 3 0 4436 2914 6453 6453 4755 9829 9829 9829 i
* 207.46.32.34 0 8075 6453 4755 9829 9829 9829 i
* 66.59.190.221 0 6539 6453 4755 9829 9829 9829 i
* 12.0.1.63 0 7018 6453 4755 9829 9829 9829 i
* 208.74.64.40 0 19214 2828 6453 4755 9829 9829 9829 i
* 203.181.248.168 0 7660 2516 6453 4755 9829 9829 9829 i
* 66.185.128.48 111 0 1668 6453 4755 9829 9829 9829 i
* 134.222.87.1 0 286 6453 4755 9829 9829 9829 i
* 157.130.10.233 0 701 6453 4755 9829 9829 9829 i
* 114.31.199.1 0 0 4826 6939 1299 6453 4755 9829 9829 9829 i
* 89.149.178.10 10 0 3257 6453 4755 9829 9829 9829 i
* 154.11.98.225 0 0 852 3561 6453 4755 9829 9829 9829 i
* 202.249.2.86 0 7500 2497 6453 4755 9829 9829 9829 i
* 154.11.11.113 0 0 852 3561 6453 4755 9829 9829 9829 i
* 144.228.241.130 0 1239 6453 4755 9829 9829 9829 i
* 217.75.96.60 0 0 16150 1299 6453 4755 9829 9829 9829 i
* 207.172.6.20 0 0 6079 3356 6453 4755 9829 9829 9829 i
* 206.24.210.102 0 3561 6453 4755 9829 9829 9829 i
* 195.66.232.239 0 5459 6453 4755 9829 9829 9829 i
* 208.51.134.254 2523 0 3549 6453 4755 9829 9829 9829 i
* 207.172.6.1 0 0 6079 3356 6453 4755 9829 9829 9829 i
* 216.218.252.164 0 6939 1299 6453 4755 9829 9829 9829 i
* 203.62.252.186 0 1221 4637 6453 4755 9829 9829 9829 i
*> 66.110.0.86 0 6453 4755 9829 9829 9829 i
* 164.128.32.11 0 3303 6453 4755 9829 9829 9829 i
* 202.232.0.2 0 2497 6453 4755 9829 9829 9829 i

 

Routing table for 117.192.0.0/20:

Network Next Hop Metric LocPrf Weight Path
* 117.192.0.0/20 193.0.0.56 0 3333 3356 6453 9829 i
* 194.85.102.33 0 3277 3216 6453 9829 i
* 194.85.40.15 0 3267 174 6453 9829 i
* 129.250.0.11 6 0 2914 6453 9829 i
* 128.223.253.10 0 3582 3701 3356 6453 9829 i
* 4.69.184.193 0 0 3356 6453 9829 i
* 209.124.176.223 0 101 101 2914 6453 9829 i
* 69.31.111.244 3 0 4436 2914 6453 9829 i
* 207.46.32.34 0 8075 6453 9829 i
* 66.59.190.221 0 6539 6453 9829 i
* 12.0.1.63 0 7018 6453 9829 i
* 208.74.64.40 0 19214 2828 6453 9829 i
* 203.181.248.168 0 7660 2516 209 6453 9829 i
* 66.185.128.48 111 0 1668 6453 9829 i
* 134.222.87.1 0 286 6453 9829 i
* 157.130.10.233 0 701 6453 9829 i
* 114.31.199.1 0 0 4826 6939 1299 6453 9829 i
* 144.228.241.130 0 1239 6453 9829 i
* 89.149.178.10 10 0 3257 6453 9829 i
* 154.11.98.225 0 0 852 2914 6453 9829 i
* 202.249.2.86 0 7500 2497 6453 9829 i
* 154.11.11.113 0 0 852 2914 6453 9829 i
* 217.75.96.60 0 0 16150 1299 6453 9829 i
* 207.172.6.20 0 0 6079 3356 6453 9829 i
* 195.66.232.239 0 5459 6453 9829 i
*> 66.110.0.86 0 6453 9829 i
* 216.218.252.164 0 6939 1299 6453 9829 i
* 206.24.210.102 0 3561 6453 9829 i
* 203.62.252.186 0 1221 4637 6453 9829 i
* 202.232.0.2 0 2497 6453 9829 i
* 208.51.134.254 2523 0 3549 6453 9829 i
* 207.172.6.1 0 0 6079 3356 6453 9829 i

 

 

Looking at table 1 for /18 – Clearly path is always via 6453 > 4755 > 9829 and then prepending. This is for sure BSNL’s transit links inside India since AS4755 is Tata-VSNL and is present only inside India (as far as I know!). Although it seems like /18 is not being announced to anyone else other then Tata-VSNL in for this subnet but I am sure there are some other prefixes which are announced to Reliance and Airtel as well. 

 

Next looking at table 2 for /20 – path is always 6453 > 9829 with no prepending. Clearly this is IPLC link since AS6453 is Tata Comm outside India and they usually do not connect to anyone inside India on 6453 but rather via Tata-VSNL AS4755 backbone. Thus likely 6453 > 9829 (direct with no AS4755 in between) is where BSNL is purchasing bandwidth outside India over IPLC. 

 

Now since /18 is less specific and even has long AS path – direct transit upstream link via Tata > Tata-VSNL > BSNL is being less preferred and IPLC is more preferred. 

 

There are also cases of /20’s where BSNL is not doing any prepends and announcing it to VSNL directly which actually is good since Tata AS6453 is connected to more networks in Asia, Europe and North America. While BSNL’s IPLC link seems only to London, New York and Los Angeles which causes issues in return paths (world > BSNL) entery points and eventually increases latency for all Asian traffic.

 

One of prefixes which is announced correctly –  117.200.48.0/20

Network Next Hop Metric LocPrf Weight Path
* 117.200.48.0/20 66.59.190.221 0 6539 6453 4755 9829 ?
* 164.128.32.11 0 3303 6453 4755 9829 ?
* 128.223.253.10 0 3582 3701 3356 6453 4755 9829 i
* 193.0.0.56 0 3333 3356 6453 4755 9829 i
* 194.85.102.33 0 3277 3216 6453 4755 9829 ?
* 194.85.40.15 0 3267 3356 6453 4755 9829 i
* 129.250.0.11 6 0 2914 6453 6453 4755 9829 ?
* 4.69.184.193 0 0 3356 6453 4755 9829 i
* 209.124.176.223 0 101 101 3356 6453 4755 9829 i
* 69.31.111.244 3 0 4436 2914 6453 6453 4755 9829 ?
* 207.46.32.34 0 8075 6453 4755 9829 ?
* 12.0.1.63 0 7018 6453 4755 9829 ?
* 208.74.64.40 0 19214 2828 6453 4755 9829 ?
* 203.181.248.168 0 7660 2516 6453 4755 9829 ?
* 66.185.128.48 111 0 1668 6453 4755 9829 ?
* 134.222.87.1 0 286 6453 4755 9829 ?
* 157.130.10.233 0 701 6453 4755 9829 ?
* 114.31.199.1 0 0 4826 6939 1299 6453 4755 9829 i
* 89.149.178.10 10 0 3257 6453 4755 9829 ?
* 154.11.98.225 0 0 852 1299 6453 4755 9829 ?
* 202.249.2.86 0 7500 2516 6453 4755 9829 ?
* 154.11.11.113 0 0 852 1299 6453 4755 9829 ?
* 144.228.241.130 0 1239 6453 4755 9829 ?
* 217.75.96.60 0 0 16150 1299 6453 4755 9829 i
* 207.172.6.20 0 0 6079 3356 6453 4755 9829 i
* 195.66.232.239 0 5459 6453 4755 9829 ?
* 208.51.134.254 2523 0 3549 6453 4755 9829 ?
* 207.172.6.1 0 0 6079 3356 6453 4755 9829 i
* 202.232.0.2 0 2497 6453 4755 9829 ?
*> 66.110.0.86 0 6453 4755 9829 ?
* 216.218.252.164 0 6939 1299 6453 4755 9829 i
* 206.24.210.102 0 3561 6453 4755 9829 ?
* 203.62.252.186 0 1221 4637 6453 4755 9829 ?

 

Well that’s all for now. With hope that your section for /20 is announced to everyone – have a good night! 🙂

11 Mar

BSNL routing messup at NIXI Delhi

Finally back in village location.

 

Was just looking around and saw BSNL having really crazy routing. I looked around and saw this:

NIXI Looking Glass – show ip bgp neighbors 218.100.48.15 routes

Router: NIXI Delhi (Noida)

Command: show ip bgp neighbors 218.100.48.15 routes

 

Total number of prefixes 0

 

 

Clearly BSNL is NOT announcing any prefix at NIXI Delhi at all. Thus if one has to send packets to BSNL in North area either it will be via transit (Tata/VSNL) or via any other peering NIXI exchange in Mumbai or Chennai.

 

Example of messed up routes (trace from Haryana)

Anurags-MacBook-Pro:~ anurag$ traceroute -a k.root-servers.net.
traceroute to k.root-servers.net (193.0.14.129), 64 hops max, 52 byte packets
1 [AS1] 10.0.0.1 (10.0.0.1) 3.308 ms 2.377 ms 1.767 ms
2 [AS9829] 117.207.184.1 (117.207.184.1) 114.369 ms 25.225 ms 25.222 ms
3 [AS9829] 218.248.173.38 (218.248.173.38) 111.460 ms 104.474 ms 200.114 ms
4 [AS4755] 115.114.89.17.static-mumbai.vsnl.net.in (115.114.89.17) 100.342 ms 101.665 ms 100.533 ms
5 [AS3549] 172.29.252.33 (172.29.252.33) 123.682 ms
[AS0] 172.31.19.126 (172.31.19.126) 121.781 ms
[AS3549] 172.29.252.33 (172.29.252.33) 120.371 ms
6 [AS0] 172.25.83.37 (172.25.83.37) 134.045 ms 128.859 ms 131.228 ms
7 [AS9430] 203.190.136.17 (203.190.136.17) 336.859 ms 350.994 ms 399.309 ms
8 [AS25152] k.root-servers.net (193.0.14.129) 351.069 ms 387.565 ms 463.440 ms

Anurags-MacBook-Pro:~ anurag$ traceroute -a tulip.net
traceroute to tulip.net (116.214.26.243), 64 hops max, 52 byte packets
1 [AS1] 10.0.0.1 (10.0.0.1) 3.134 ms 1.846 ms 1.410 ms
2 [AS9829] 117.207.184.1 (117.207.184.1) 23.865 ms 25.057 ms 23.969 ms
3 [AS9829] 218.248.173.42 (218.248.173.42) 25.635 ms * 24.826 ms
4 [AS9829] 218.248.246.130 (218.248.246.130) 72.688 ms 71.779 ms 76.546 ms
5 [AS4755] 115.113.128.17.static-mumbai.vsnl.net.in (115.113.128.17) 94.713 ms 144.059 ms 93.960 ms
6 [AS0] 172.31.17.106 (172.31.17.106) 122.504 ms 125.455 ms 160.892 ms
7 [AS0] 172.25.83.37 (172.25.83.37) 124.495 ms 124.729 ms 123.955 ms
8 [AS4755] 115.113.248.250.static-delhi.vsnl.net.in (115.113.248.250) 127.256 ms 128.388 ms 127.253 ms
9 * * *
10 [AS37986] 116.214.26-243.del.tulipconnect.com (116.214.26.243) 126.804 ms 147.704 ms 143.994 ms
Anurags-MacBook-Pro:~ anurag$ 

 

So clear lot of traffic exchange between Northern networks are happening from far down in South.

 

Anyways time to do some more interesting work for now! 😉

 

 

***Update***

BSNL seems to be announcing 500+ prefixes now at NIXI Delhi and routes are again pretty good. And I have no idea why they did this!

Router: NIXI Delhi (Noida)

Command: show ip bgp neighbors 218.100.48.15 routes

BGP table version is 2146799, local router ID is 218.100.48.1
Status codes: s suppressed, d damped, h history, * valid, > best, i – internal,
r RIB-failure, S Stale
Origin codes: i – IGP, e – EGP, ? – incomplete

Network Next Hop Metric LocPrf Weight Path
*> 49.50.64.0/18 218.100.48.15 0 9829 55470 i
*> 59.89.32.0/20 218.100.48.15 0 0 9829 ?
*> 59.89.48.0/20 218.100.48.15 0 0 9829 ?
*> 59.89.64.0/20 218.100.48.15 0 0 9829 ?
*> 59.89.80.0/20 218.100.48.15 0 0 9829 ?
*> 59.89.96.0/20 218.100.48.15 0 0 9829 ?
*> 59.89.112.0/20 218.100.48.15 0 0 9829 ?
*> 59.89.208.0/20 218.100.48.15 0 0 9829 ?
*> 59.90.0.0/20 218.100.48.15 0 0 9829 ?
*> 59.90.16.0/20 218.100.48.15 0 0 9829 ?
*> 59.90.48.0/20 218.100.48.15 0 0 9829 ?
*> 59.90.80.0/20 218.100.48.15 0 0 9829 ?
*> 59.90.96.0/20 218.100.48.15 0 0 9829 ?
*> 59.90.112.0/20 218.100.48.15 0 0 9829 ?
*> 59.90.128.0/20 218.100.48.15 0 0 9829 ?
*> 59.90.144.0/20 218.100.48.15 0 0 9829 ?
*> 59.90.160.0/20 218.100.48.15 0 0 9829 ?
*> 59.90.176.0/20 218.100.48.15 0 0 9829 ?
*> 59.90.184.0/24 218.100.48.15 0 9829 i