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Community Member

trunk with juniper device - mtu issue

hi all,

I have an issue with a trunk between a catalyst 2960 running iso 12.4, and an SSG 320 from juniper.

the juniper device is connected via a trunk to the cisco on the port fastethernet 0/1 configured as below :

interface FastEthernet0/1

switchport mode trunk

switchport trunk allowed vlan 10,11

there is a windows workstation connected to the port 0/2 with the config below :

interface FastEthernet0/2

switchport mode access

switchport access vlan 10

but the thing is that as I try to send a ping from the juniper with a size bigger than 1468 bytes, it looks like the ping is dropped by the cisco.

I also cannot send big pings from the pc workstation, unless I set the mtu manually to 1496.

how can I set the cisco to accept the traffic between the juniper and the pc ?




Re: trunk with juniper device - mtu issue

You can issue the vlan vlan-id mtu mtu-size command to increase the maximum transmission unit (mtu) size upto 2018 bytes , so that the switch does not drop the large frames. And also verify both side settings are configured properly.

Community Member

Re: trunk with juniper device - mtu issue

it looks like there is a bug with the juniper device.

thanks for the reply.

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