01-22-2023 07:27 AM
Hello,
A router in LNS configuration with the following configuration :
vpdn enable
!
vpdn-group TEST
accept-dialin
protocol l2tp
virtual-template 1
source-ip A.B.C.D
local name L2TP-1
lcp renegotiation always
no l2tp tunnel authentication
ip mtu adjust
!
interface Virtual-Template1
ip unnumbered Loopback1
no ip redirects
no ip proxy-arp
ip mtu 1300
ip verify unicast source reachable-via rx
ip tcp adjust-mss 1260
ppp mtu adaptive
ppp authentication chap ppp-radius
ppp authorization network-radius
ppp multilink
ppp multilink fragment disable
!
Does the Virtual-Template1 interface auto-configure the client with the MTU (1300) ? I ask the question because I have a doubt...
On the router (client ppp) I can ping higher than 1300 ! The ping works up to 1500 :
Cisco_RTR#ping 8.8.8.8 size 1500 df-bit
Type escape sequence to abort.
Sending 5, 1500-byte ICMP Echos to 8.8.8.8, timeout is 2 seconds:
Packet sent with the DF bit set
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 104/113/128 ms
Thank you for your explanation
01-22-2023 07:41 AM
ppp mtu adaptive
this command make the issue,
adaptive mtu meaning that LNS use the MTU the client use not the mtu config under the virtual-template.
this I think issue here, remove it and check again
01-22-2023 07:57 AM
No, it doesn't change anything, I've already done the test with or without ppp mtu adaptive.
The test client router uses a virtual-ppp interface with pseudowire-class. Could the problem come from this ?
01-22-2023 08:00 AM
with and without, are you force the client to initiate new PPP ?
01-22-2023 08:25 AM
Of course I reloaded the test client router !
01-22-2023 08:40 AM
can I see the LNS/LAC and client config ?
01-22-2023 08:50 AM
There is no LAC... The configuration of the LNS/L2TP server is in the first message.
Here the configuration of test router :
l2tp-class TEST
!
pseudowire-class CL-PW
encapsulation l2tpv2
protocol l2tpv2 TEST
ip local interface GigabitEthernet8
!
interface GigabitEthernet8
description * WAN *
ip address dhcp
no ip redirects
no ip proxy-arp
ip nat outside
ip virtual-reassembly in
duplex auto
speed auto
no cdp enable
!
interface Virtual-PPP1
ip address negotiated
ip nat outside
ip virtual-reassembly in
no cdp enable
ppp chap hostname cisco@test.com
ppp chap password 7 045A11031D3555
pseudowire A.B.C.D 10 encapsulation l2tpv2 pw-class CL-PW
!
01-23-2023 07:01 AM
No idea ?
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