I'm looking for the limits on a l2tpv3 xconnect layer2 connection of the cisco 881 by means of a lab setup.
2 cisco 881 directly connected to each other with their Fa4
the Fa3 in a vlan, with the vlan interface xconnected to the other cisco. ipsec is not used yet
so far I learned that fragmentation takes down the receiving cisco (who was to defragment the packet).
If I lower the MTU on the testing pc (connected to Fa3), I get full 100mbit performance.
If I raise the MTU of both the Fa4 interfaces (something I am suprised is possible, since this is not gig) I get 50 mbit performance. And I wonder why, because the cisco is not doing fragmentation anymore, (confirmed in debug).
Does the cisco switch back to cpu performance instead of HW performance is you raise the MTU?
how do you explain the possibility of raising the MTU on a Fa interface?
using Version 15.2(2)T in adv ip services licencing (trial)
relevant config, reason why choosen manual l2tp is becauce once working like expected, one cisco is going to be replaced by linux
pseudowire-class l2tpv3
encapsulation l2tpv3
interworking ethernet
protocol none
ip local interface FastEthernet4
interface FastEthernet4
mtu 2000
ip address 192.168.1.1 255.255.255.252
ip mtu 1980
ip virtual-reassembly in
load-interval 30
duplex auto
speed auto
interface FastEthernet3
switchport access vlan 100
no ip address
interface Vlan100
no ip address
no autostate
xconnect 192.168.1.2 30 encapsulation l2tpv3 manual pw-class l2tpv3
l2tp id 1 1
l2tp cookie local 4 0
l2tp cookie remote 4 0
kind regards
Arne
