07-10-2007 08:08 AM - edited 02-21-2020 03:08 PM
I have sucessfully stablished the VPN tunnel between the two sites. Also I am able to do a ping test to both Routers Inside Interface with 100% success, but when I try to ping another device I got packets lost 50%.
I am Using a 871 and a 1841 Both on DSL on 512 upstream.
07-10-2007 07:32 PM
Hello.
I assume you mean the following
From LAN side on 871 - ping to router 871 100%
From LAn on 871 - ping to router 1841 50% loss.
From LAN side on 1841 - ping to router 1841 100%
Is it possible to confirm that a ping from the 1841 external interface to the 871 external interface does not drop packets?
Its easy to not drop packets on the internal interface. The DSL maybe indicative of service issues. Is the DSl symetrical?
07-10-2007 08:07 PM
Well let me explain better.
When I ping the router interface on either of the LANs it works well.
Also if I do a telnet on the router:
ping 192.168.100.254 source 192.168.1.254;
a ping between the routers via the VPN, I get 100% replys.
When I try to ping from a station(LAN) to a station on the other site is when I get 50% - 40% loss.
I have a paradyne modem from the ISP doing a DMZ to the 871 and the 1841 have a WIC adsl.
The Internet conection is Asymetrical DSL.
07-10-2007 08:15 PM
MTU size of the pings? Can you test with differing sizes?
07-10-2007 08:34 PM
This is the actual screen on the station on one of the sites. The 192.168.1.254 is the remote site inside interface address. The Maximun Size without Framenting is 1370 but still I got some packet loss.
Pinging 192.168.1.254 with 1370 bytes of data:
Reply from 192.168.1.254: bytes=1370 time=136ms TTL=254
Request timed out.
Reply from 192.168.1.254: bytes=1370 time=143ms TTL=254
Request timed out.
Ping statistics for 192.168.1.254:
Packets: Sent = 4, Received = 2, Lost = 2 (50% loss),
Approximate round trip times in milli-seconds:
Minimum = 136ms, Maximum = 143ms, Average = 139ms.
This is the ping from router a inside Interface to router b inside interface:
Sending 5, 1370-byte ICMP Echos to 192.168.1.254, timeout is 2 seconds:
Packet sent with a source address of 192.168.100.254
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 68/70/72 ms
07-10-2007 08:41 PM
You'll need to confirm MTU sizing for each interface.
make sure you have no issues with performance from the local host to the local router.
07-10-2007 08:50 PM
The perfomarce on from the local to the router on both sites are fine.
When you mean MTU on interfaces, are the interfaces the inside or outside? On the ATM or Dialer.
07-10-2007 08:52 PM
ATM and dialer
07-10-2007 09:00 PM
ATM0/0/0:
MTU 4470, Sub MTU 1300.
Dialer0:
MTU 1500
Should I change de MTU to 1370 on the 1841 ATM and Dialer0?
07-10-2007 09:08 PM
yes.
check each end.
07-10-2007 09:17 PM
I already changed on the 1841, still the same but I need to change it on the 871 and also may need to check the paradyne modem of the ISP on the midle it can include some misteries to the issues.
07-12-2007 04:28 AM
I tried to change the MTU on the Cisco 871 but I can't is seem the MTU can't be change on these Router.
I tried on the interface and on the vlan.
07-18-2007 04:05 AM
It's an IOS bug, you can make a test and disable IP CEF, usually it works, but it's only a workaround to get it working for real upgrade the IOS.
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