Hello,
I use two 7600 as P routers.
These are configured with routed interfaces:
interface Gi2/1
mtu 1520
interface Gi2/1.15
no switchport
ip address 1.2.3.4 255.255.255.0
mpls ip
Now want to use SVI:
vlan 1145
mtu 1520
!
interface vlan 1145
ip address 1.2.3.4 255.255.255.0
tag-switching ip
mtu 1520
!
conf t
interface Gi2/1
switchport
switchport trunk encapsulation dot1q
switchport trunk allowed vlan 1145
switchport mode trunk
switchport nonegotiate
mtu 9216
no ip address
speed nonegotiate
no shutdown
!
I understand mtu 9216 as the hardware mtu.
1520-sized ICMP packets with df-bit are ok with:
vlan 1145
mtu 1520
interface vlan 1145
mtu 1520
and also ok with:
vlan 1145
mtu 1500
interface vlan 1145
mtu 1520
but not OK if the mtu on interface vlan 1145 is not 1520.
So, what is the difference between the mtu 1520 command under interface vlan 1145 and the mtu 1520 command under vlan 1145 configuration ?
Is there any issues (performances) using 7600 as P router with SVI ?
Thanks