Networking

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

The first route in table seems pretty weird. AS path is 33765 1299 3549 9829 i.e clearly AS33765 sitting in middle of AS6453 and AS1299. This must be a route leak since Tata AS6453 and Telia AS1299 are way too bigger then Tanzania telecom and hence there’s no possibility of Tata transitting via Tanzania telecom. Though issue seems for just one specific route for BSNL which Tanzania telecom is learning from Telia, which further is getting from Global Crossing AS3549 (one of upstreams of BSNL). 

Last week I saw an interesting post at APNIC mailing list about IRINN (recently formed NIR in Indian region). 

Poster Jimmy was concerned about IRINN’s netname

inetnum: 0.0.0.0 - 255.255.255.255  
netname: IRINN-BROADCAST-ADDRESSES  
descr: Broadcast addresses  
descr: These addresses cannot (should not) be routed on the Internet.  
country: IN  
admin-c: IH1-IN  
tech-c: IH1-IN  
status: ALLOCATED PORTABLE  
remarks: send spam and abuse report to info@irinn.in  
mnt-by: IRINN-HM  
mnt-irt: IRT-IRINNHM-IN  
mnt-lower: IRINN-HM  
changed: hostmaster2@irinn.in 20130420  
source: IRINN

As per first two lines entire IPv4 address space i.e 0.0.0.0/0 (ranging from 0.0.0.0 to 255.255.255.255) was put as IRINN-Broadcast while expected was IANA broadcast (since IANA sits on top in this RIR & NIR hierarchy).

And college started after pretty good holi holidays. Again having bit painful time due to hot weather and this is just start of summers. Well all I can hope is that there won’t be voltage issues in village again (like last time). And just to make sure on that part - I have put 2 RTI’s asking Power department about their preparation details. :)

Anyways coming on blog post topic for the day - the effect of “next-hop-self” at an IXP when there are peers as well as transit customers of a network. Just to be clear in start - this post will stick to technical side of it and without going into IXP policy side of it.

Fest time at college - Good since I get lot of free time to spend around looking at routing tables. It’s always interesting since last week was full of some major submarine cable cuts and has huge impact on Indian networks.

Anyways, an interesting issue to post today about Global IPv6 routing . There are “dark spots” in global IPv6 routing because of peering dispute between multiple tier 1 ISPs involving Hurricane Electric (AS6939) & Cogent Communications (AS174).  What’s happening here is that both tier 1 providers failed to reach on agreement to keep peering up in case of IPv6. This has resulted in parts of global IPv6 internet where packets from one network (and it’s downstream) can’t reach other network or their downsteam singled hommed networks. 

Today a friend from Pakistan informed about SMW4 outage. He reported about issues in Pakistan.

It seems like SMW4 is damaged near Egypt and that is what causing high load on East Asian routes giving pretty high latency.

I am at my home and sitting BSNL’s network and latency with Europe has jumped terribly to 700-800ms. Right now I do not see a direct route to Europe and it’s rather taking East Asia > US > Europe routes right now on other cable networks.