Solved

Cisco Site to Stite VPN Tunnel Drops Alternating Pings

Posted on 2010-11-08
2
881 Views
Last Modified: 2012-05-10
Here is a summary of the current problem I have with my Cambodia office.  In SF, we have a Cisco 5510.  In Cambodia (KH), there is a Cisco 2821.

1) All pings from SF to KH result in alternating packet loss (VPN Tunnel);
2) All pings from KH to Internet are fine (No Tunnel);
3) All pings from KH to SF result in alternating packet loss (VPN Tunnel);
4) Pings from SF to inside interface and outside interface are fine (no loss, VPN Tunnel).
5) Increasing ping size to 1500 (ping x.x.x.x -l 1500) results in no packet loss (VPN Tunnel).
6) I have removed all network gear on the KH side and had a user hook a laptop direct to the 2821.  Same issues.
7) this tunnel had been working for 2+ years with no issues.  No changes on the 5510 or ISP in SF.  I am not sure about the ISP in KH - I cannot get an answer.

Z:\>ping 10.3.0.2

Pinging 10.3.0.2 with 32 bytes of data:
Reply from 10.3.0.2: bytes=32 time=201ms TTL=62
Request timed out.
Reply from 10.3.0.2: bytes=32 time=201ms TTL=62
Request timed out.

Ping statistics for 10.3.0.2:
    Packets: Sent = 4, Received = 2, Lost = 2 (50% loss),
Approximate round trip times in milli-seconds:
    Minimum = 201ms, Maximum = 201ms, Average = 201ms


Z:\>ping 10.3.0.2 -l 1500

Pinging 10.3.0.2 with 1500 bytes of data:
Reply from 10.3.0.2: bytes=1500 time=208ms TTL=62
Reply from 10.3.0.2: bytes=1500 time=219ms TTL=62
Reply from 10.3.0.2: bytes=1500 time=208ms TTL=62
Reply from 10.3.0.2: bytes=1500 time=208ms TTL=62

Ping statistics for 10.3.0.2:
    Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
    Minimum = 208ms, Maximum = 219ms, Average = 210ms
0
Comment
Question by:wdurrett
2 Comments
 
LVL 3

Accepted Solution

by:
n7okn earned 500 total points
Comment Utility
You might try putting this on the outside Interface on both routers:

ip tcp adjust-mss 1452


0
 
LVL 10

Author Closing Comment

by:wdurrett
Comment Utility
Awesome.  I only had to add it to the KH router.  All is good now.

Here is the Cisco write-up:
http://www.cisco.com/en/US/docs/ios/12_2t/12_2t4/feature/guide/ft_admss.html
0

Featured Post

Zoho SalesIQ

Hassle-free live chat software re-imagined for business growth. 2 users, always free.

Join & Write a Comment

The Cisco RV042 router is a popular small network interfacing device that is often used as an internet gateway. Network administrators need to get at the management interface to make settings, change passwords, etc. This access is generally done usi…
I recently attended Cisco Live! in Las Vegas, a conference that boasted over 28,000 techies in attendance, and a week of hands-on learning hosted by a solid partner with which Concerto goes to market.  Every year, Cisco displays cutting-edge technol…
After creating this article (http://www.experts-exchange.com/articles/23699/Setup-Mikrotik-routers-with-OSPF.html), I decided to make a video (no audio) to show you how to configure the routers and run some trace routes and pings between the 7 sites…
After creating this article (http://www.experts-exchange.com/articles/23699/Setup-Mikrotik-routers-with-OSPF.html), I decided to make a video (no audio) to show you how to configure the routers and run some trace routes and pings between the 7 sites…

771 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question

Need Help in Real-Time?

Connect with top rated Experts

13 Experts available now in Live!

Get 1:1 Help Now