[c-nsp] Fw: MTU problem on Virtual-Access interfaces

[Gyebnár Krisztián]

Hi all,

We have a litle problem with our NPE-G1, We use this router to terminate cca 3000 L2TP sessions and PPPoE.
Some days ago, many customer have a problem with VPN, browsing, etc...We try to find the problem what's wrong. We check the customer, also some CPE router config..., but we found interesting things in our Termination router: The Virtual-access interface MTU is BIGGER than than his mother(Virtual-Template 1) MTU !!!

If I clear manualy the Vi intarface; next time when the Router come up the interface will be ok with MTU of 1492...
and some time later the interface go wrong and will be again MTU of 1512 :-( 
I dont know how this is possible, because of the config is very simple without any fancy feature and works fine couple of times...

Any idea ???


THX 

gyebi

Virtual-Access61 is up, line protocol is up
  Hardware is Virtual Access interface
  Interface is unnumbered. Using address of GigabitEthernet0/1 (195.228.xx.yy)
  MTU 1512 bytes, BW 3735 Kbit, DLY 100000 usec,
     reliability 255/255, txload 1/255, rxload 1/255
  Encapsulation PPP, LCP Open, multilink Closed
  Open: IPCP
  PPPoVPDN vaccess, cloned from Virtual-Template1
  Vaccess status 0x44
.......

interface Virtual-Template1
 mtu 1492
 ip unnumbered GigabitEthernet0/1
 no ip unreachables
 no logging event link-status
 peer default ip address pool adsl1
 keepalive 30
 ppp authentication pap
 ppp multilink
 no clns route-cache

!
vpdn-group adsl
! Default L2TP VPDN group
! Default PPTP VPDN group
 accept-dialin
  protocol any
  virtual-template 1
 local name XXX
 lcp renegotiation on-mismatch
!

System image file is "c7200-jk9o3s-mz.123-10a.bin"