Cisco Routing

[Roel Reyes]

Hi, 

Where can i get support why is our routing to cisco.com, gets high latency compare to our upstream .

1st image: Hop 10 ~300ms (USING our IP block)          2nd image: Hop 10 ~192ms (USING our UPstream IP block)

[Georg Pauwen]

Hello,

do you experience latency when actually accessing the content on Cisco.com ? ISPs often treat PING traffic as low priority, so slow ping responses do not necessarily mean that the link is slow...

[Roel Reyes]

Hi,

Yes slow connection on cisco website. Also monitored with severe packet loss.

[Roel Reyes]

[Georg Pauwen]

Hello,

try and send different packet sizes with the DF bit set, until you get the value where paclets are not fragemented anymore:

C:\Users\pauwe>ping -l 1500 -f www.cisco.com

Pinging e2867.dsca.akamaiedge.net [104.98.129.232] with 1500 bytes of data:
Packet needs to be fragmented but DF set.
Packet needs to be fragmented but DF set.
Packet needs to be fragmented but DF set.
Packet needs to be fragmented but DF set.

Ping statistics for 104.98.129.232:
Packets: Sent = 4, Received = 0, Lost = 4 (100% loss),

C:\Users\pauwe>ping -l 1472 -f www.cisco.com

Pinging e2867.dsca.akamaiedge.net [104.98.129.232] with 1472 bytes of data:
Reply from 104.98.129.232: bytes=1472 time=124ms TTL=57
Reply from 104.98.129.232: bytes=1472 time=13ms TTL=57
Reply from 104.98.129.232: bytes=1472 time=12ms TTL=57
Reply from 104.98.129.232: bytes=1472 time=12ms TTL=57

Ping statistics for 104.98.129.232:
Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 12ms, Maximum = 124ms, Average = 40ms

[Roel Reyes]

Hi,

Is this fragmentation can cause high latency?
As per my post, there was a sudden increase in latency in hop 10, that is why i think it’s a routing issue.

[pieterh]

seems a boundary between two AS, both routers seem to lay in the Cisco network?

72.163.0.5

everse DNS (PTR)	rcdn9-cd1-dmzbb-gw1-ten1-1.cisco.com

4.59.34.66

Reverse DNS (PTR)	CISCO-SYSTE.edge5.Dallas3.Level3.net

[Joseph W. Doherty]

". . . routing issue."

Perhaps as simple as a congested link. If so, often provider monitoring would inform them of this (and if it did, they may or may not have plans to remediate [complaining can sometimes get an upgrade scheduled]) but sometimes it's missed by provider monitoring (and complaining about it might also get the issue remediated).

[Roel Reyes]

yea maybe, i don't still don't understand why using other ip block (upstream peering IP) results to low latency (image 2 - hop 10 - 192ms ) and other IP on looking glass, compare to different ip block (customer public IP) results to high latency (image 1 - hop 10 - 300ms) and it's constant.

Can this be IP blacklisting? causing it to de-prioritize the packets?

[Joseph W. Doherty]

I haven't looked carefully, but when using another IP, you're sure the same link is being used (at the problem router) in those cases. (BTW, I used to work for a large provider, and it wasn't unknown that a "link" between routers was multiple physical links, and occassionally one of those links has a physical issue.)

[Roel Reyes]

Hi yes we're using same link, 1st image (300ms) is a customer of the 2nd image (192ms) via IP transit connection. I'm suspecting that it is the return path from cisco edge link (72.163.0.5) to the customer route.

[pieterh]

some remark: I had a similar issue where the problem occurred between offices in Europe and Africa.

The Africa office had two providers, where the primary provider link latency was more than double the value of the backup!

I did not succeed in making improvement, because both Europe and Africa provider said their configuration was in order.

NB! as traffic incoming to the African country was censored, not purely routing was involved. It could be the censoring system runs out of resources.

I think you better contact Cisco directly to address the issue.

[Roel Reyes]

Yea, that is why I’m trying to post in this forum to get info with you guys on how can i contact cisco regarding latency/routing issues, and i really appreciate your inputs

[pieterh]

Hmmm... Not sure.... 

as this is about accessing Cisco information you might try the feedback button