Today I noticed some traffic on my blog from a link from Broadband forum.
Here’s what poster wrote:
I made a thread a few days ago complaining about BSNL’s horrible routing. Well it looks like it has been fixed. I thank all the guys who made efforts to bring this to BSNL’s notice. Especially Anurag Bhatia who highlighted the issue with much detail on his blog
It’s late night here in India. I am having final 8th semester exams and as usual really bored!
Though this time we have interesting subjects but still syllabus is pretty boring spreading across multiple books, notes and pdf’s. Anyways I will be out of college after June which sounds good.
Tonight, I found a routing glitch. Yes a routing glitch!! :)
These issues somehow keep my life in orbit and give a good understanding on how routing works over the Internet.
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:
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:
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.