Tata

Last month I noticed quite high latency with Cisco’s OpenDNS from my home fibre connection. The provider at home is IAXN (AS134316) which is peering with content folks in Delhi besides transit from Airtel.

ping -c 5 208.67.222.222
PING 208.67.222.222 (208.67.222.222) 56(84) bytes of data.
64 bytes from 208.67.222.222: icmp_seq=1 ttl=51 time=103 ms
64 bytes from 208.67.222.222: icmp_seq=2 ttl=51 time=103 ms
64 bytes from 208.67.222.222: icmp_seq=3 ttl=51 time=103 ms
64 bytes from 208.67.222.222: icmp_seq=4 ttl=51 time=103 ms
64 bytes from 208.67.222.222: icmp_seq=5 ttl=51 time=103 ms
--- 208.67.222.222 ping statistics ---
5 packets transmitted, 5 received, 0% packet loss, time 4005ms
rtt min/avg/max/mdev = 103.377/103.593/103.992/0.418 ms

	

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A few weeks back I got in touch with Marc from Meghalaya. He offered to host RIPE Atlas probe at Shillong and that’s an excellent location which isn’t there on RIPE Atlas coverage network yet. It took around 5 days for the probe to reach Shillong from Haryana. I think probably this probe is the one at the most beautiful place in India. :) Now that probe is connected, I thought to look into routing which is super exciting for far from places like Shillong. Marc has a BSNL FTTH connection & mentioned about not-so-good latency. Let’s trace to 1st IP of the corresponding /24 pool on which probe is hosted:

On weekend  I was looking at BGP Instability Report data. As usual (and unfortunately) BSNL tops that list. BSNL is the most unstable autonomous network in the world. In past, I have written previously about how AS9829 is the rotten IP backbone.

This isn’t a surprise since they keep on coming on top but I think it’s well worth a check on what exactly is causing that. So I looked into BGP tables updates published on Oregon route-views from 21st May to 27th May and pulled data specifically for AS9829. I see zero withdrawals which are very interesting. I thought there would be a lot of announcements & withdrawals as they switch transits to balance traffic. If I plot the data, I get following chart of withdrawals against timestamp. This consists of summarised view of every 15mins and taken from 653 routing update dumps. It seems not feasible to graph data for 653 dumps, so I picked top 300.

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.

Last night I was looking at routing tables and saw a interesting case where for a specific route.

Here’s what I got from Tata’s AS6453 looking glass:

Router: gin-ldn-core4  
Site: UK, London, LDN  
Command: show ip bgp 117.219.227.229

BGP routing table entry for 117.219.224.0/20  
Bestpath Modifiers: deterministic-med  
Paths: (4 available, best #4)  
Multipath: eBGP  
17 18 19

33765 1299 3549 9829, (received-only)  
ix-3-1-2.core4.LDN-London. from ix-3-1-2.core4.LDN-London. (ix-3-1-2.core4.LDN-London.)  
Origin IGP, valid, external

4755 9829  
mlv-tcore2. (metric 3605) from l78-tcore2. (66.110.10.234)  
Origin IGP, valid, internal  
Community:  
Originator: 66.110.10.215

4755 9829  
mlv-tcore2. (metric 3605) from l78-tcore1. (66.110.10.237)  
Origin IGP, valid, internal  
Community:  
Originator: 66.110.10.215

4755 9829  
mlv-tcore2. (metric 3605) from ldn-mcore3. (ldn-mcore3.)  
Origin IGP, valid, internal, best  
Community:  
Originator: 66.110.10.215

	

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