Poor performance of K-root server (Delhi node)

Anurag Bhatia
dns, networking

Seems like k-root servers are having issue again. This is not the first time BSNL is having such issues. Last year I reported issue with K root server (which was actually because of downtime at Delhi node).  

Here’s some data for today’s case:

PING 193.0.14.129 (193.0.14.129) 56(84) bytes of data. 
64 bytes from 193.0.14.129: 
icmp_req=1 ttl=44 time=309 ms 
64 bytes from 193.0.14.129: icmp_req=2 ttl=44 time=312 ms 
64 bytes from 193.0.14.129: icmp_req=3 ttl=44 time=312 ms 
64 bytes from 193.0.14.129: icmp_req=4 ttl=44 time=312 ms 
64 bytes from 193.0.14.129: icmp_req=5 ttl=44 time=313 ms 
--- 193.0.14.129 ping statistics --- 
5 packets transmitted, 5 received, 0% packet loss, time 4001ms 
rtt min/avg/max/mdev = 309.687/312.019/313.333/1.289 ms  


 

Quick NS lookup for .com zone:

dig @193.0.14.129 com.

; <<>> DiG 9.18.1-1ubuntu1.1-Ubuntu <<>> @193.0.14.129 com.
; (1 server found)
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 21791
;; flags: qr rd; QUERY: 1, ANSWER: 0, AUTHORITY: 13, ADDITIONAL: 27
;; WARNING: recursion requested but not available

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 1232
;; QUESTION SECTION:
;com.				IN	A

;; AUTHORITY SECTION:
com.			172800	IN	NS	a.gtld-servers.net.
com.			172800	IN	NS	b.gtld-servers.net.
com.			172800	IN	NS	c.gtld-servers.net.
com.			172800	IN	NS	d.gtld-servers.net.
com.			172800	IN	NS	e.gtld-servers.net.
com.			172800	IN	NS	f.gtld-servers.net.
com.			172800	IN	NS	g.gtld-servers.net.
com.			172800	IN	NS	h.gtld-servers.net.
com.			172800	IN	NS	i.gtld-servers.net.
com.			172800	IN	NS	j.gtld-servers.net.
com.			172800	IN	NS	k.gtld-servers.net.
com.			172800	IN	NS	l.gtld-servers.net.
com.			172800	IN	NS	m.gtld-servers.net.


 

Looking at traceroute:

traceroute to k.root-servers.net. (193.0.14.129), 30 hops max, 60 byte packets 
1 router.local (192.168.1.1) [AS8151/AS28513] 4.206 ms 5.041 ms 5.892 ms 
2 117.212.40.1 (117.212.40.1) [AS9829] 32.243 ms 33.918 ms 36.122 ms 
3 218.248.173.42 (218.248.173.42) [AS9829] 38.320 ms 42.492 ms 45.021 ms 
4 203.190.136.17 (203.190.136.17) [AS9430] 337.645 ms 346.152 ms 346.837 ms 
5 k.root-servers.net (193.0.14.129) [AS25152] 348.053 ms 349.664 ms 351.468 ms

Issue seems in connectivity between BSNL (AS9829) & AS9439 which belongs to Software Technology Parks Of India. Issue seems purely with BSNL and not with other major ISP’s like Bharti Airtel.  


 

Checking K-root from Airtel Delhi node:

Tue Jan 10 16:34:48 GMT+05:30 2012 
ping 193.0.14.129 Type escape sequence to abort. Sending 5, 
100-byte ICMP Echos to 193.0.14.129, timeout is 2 seconds: 
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 1/2/4 ms DEL-ISP-MPL-ACC-RTR-9#  


 

Next, traceroute from Airtel Delhi PoP to K-root:

Tue Jan 10 16:39:00 GMT+05:30 2012 
traceroute 193.0.14.129 Type escape sequence to abort. 
Tracing the route to k.root-servers.net (193.0.14.129) 
1 218.100.48.6 0 msec 4 msec 0 msec 
2 k.root-servers.net (193.0.14.129) [AS 25152] 0 msec 0 msec 0 msec 
DEL-ISP-MPL-ACC-RTR-9#

All seems pretty good for Airtel. :)  


 

Summary:

BSNL (AS9829) was earlier routing traffic directly to K-root server’s via RIPE NCC - AS25152 but because of some changes it’s now using STPI and which seems to be having badly choked port in niXi. BSNL should be using route to 25152:4   (RS-KROOT-DELHI) directly to fix this but I wonder if BSNL Network admins read my blog posts. :(


 

Update:

author: “Anurag Bhatia” url: “/2012/01/dns/poor-performance-of-k-root-server-delhi-node/”

17th Jan 2011 Issue seems fixed by now.  Routing now direct skilling STPI.