[c-nsp] Ping test with DF bit and MTU / IP MTU value

[Muhammad Atif Jauhar]

Hi,

I have very basic question related to MTU / IP MTU value and ping test with
DF bit

*Scenario: *
I have one router connected to HUB router with Link leasing from SP
*            * 1. On spoke side, we have GigaEthernet Interface with MTU
value set to 1520
             2. On HUB side, that link is terminated on layer-2 switch and
from there to router sub-interface with IP MTU value set to 1520.
             3.  Configurations on both router
*                                 a.  SPOKE Side*
*                                             *interface GigabitEthernet0/1
                                             mtu 1520
                                             bandwidth 10000
                                             ip address 192.168.0.1
255.255.255.252
                                             ip ospf network point-to-point
                                             ip ospf cost 1000
                                             ip ospf hello-interval 1
                                             ip ospf dead-interval 3
                                             ip ospf mtu-ignore
                                             duplex auto
                                             speed auto
                                             mpls ip
                                   *b. HUB Side*
*
                                             interface
GigabitEthernet0/1.100
                                             bandwidth 10000
                                             encapsulation dot1Q 100
                                             ip address 192.168.0.2
255.255.255.252
                                             ip mtu 1520
                                             ip ospf network point-to-point
                                             ip ospf cost 1000
                                             ip ospf hello-interval 1
                                             ip ospf dead-interval 3
                                             ip ospf mtu-ignore

mpls ip


*
*Issue:*

I am testing the link and face issue.
                  1. while performing ping test without df bit, I am able to
ping with size upto 18024
                  2. while performing ping test with df bit, I am able to
ping with size 1520
                  3. while performing ping test with df bit, I am able to
ping with size more than 1520

*Kindly let me know, why I am not able to ping with DF bit with size more
than 1520 (MTU value). How can I troubleshoot the issue. *
*
*
*Any comment please*
-- 
Regards,

Muhammad Atif Jauhar
(+60-10-2155076)