I believe it is not valid for Ethernet interfaces dear salbad -----Original Message----- From: juniper-nsp-boun...@puck.nether.net [mailto:juniper-nsp-boun...@puck.nether.net] On Behalf Of Mohammad Salbad Sent: Sunday, March 06, 2011 1:41 PM To: juniper-nsp@puck.nether.net Subject: [j-nsp] Layer 2 Fragmentation
Hello All I have two EX4200 switches connected back to back to each other with interfaces in trunk mode as following: Case(1) back to back connection using ethernet cable (VL11 IP: 10.1.1.1/30) EX4200 -------------------TRUNK (Ethernet)---------------------EX4200 (VL11 IP: 10.1.1.2/30) è For this case I can ping with don’t fragment option up to 1554 byte as following: ping 10.1.1.2 size 1554 do-not-fragment PING 10.1.1.2 (10.1.1.2): 1554 data bytes 1562 bytes from 10.1.1.2: icmp_seq=0 ttl=64 time=3.639 ms 1562 bytes from 10.1.1.2: icmp_seq=1 ttl=64 time=3.550 ms 1562 bytes from 10.1.1.2: icmp_seq=2 ttl=64 time=3.556 ms Case(2) back to back connection using wireless backhaul devices (VL11 IP: 10.1.1.1/30) EX4200 -------------------TRUNK (wireless backhaul)---------------------EX4200 (VL11 IP: 10.1.1.2/30) è For this case I can ping with don’t fragment option up to 1476 byte as following: ping 10.1.1.2 size 1476 do-not-fragment PING 10.1.1.2 (10.1.1.2): 1476 data bytes 1484 bytes from 10.1.1.2: icmp_seq=0 ttl=64 time=4.096 ms 1484 bytes from 10.1.1.2: icmp_seq=1 ttl=64 time=4.094 ms 1484 bytes from 10.1.1.2: icmp_seq=2 ttl=64 time=5.496 ms Switches configuration sample ge-0/0/1 { mtu 1600; ether-options { link-mode full-duplex; speed { 100m; } } unit 0 { family ethernet-switching { port-mode trunk; vlan { members [ TEST ]; } } } vlan { mtu 1600; unit 11 { family inet { address 10.1.1.1/30; } } vlans { TEST { vlan-id 11; } The case is that I didn’t change the configuration on the switches I just replaced the Ethernet cable with wireless backhaul devices and then I can’t ping with larger mtu sizes, and this is because the wireless devices I’m using for backhaul are limited to 1500 MTU size, so I’m wondering if I there is anything I can do on the switches to overcome the limitation on the wireless backhaul devices, i.e. if I can fragment the packet into smaller pieces before sending them to the wireless device and combining the packet on the other end (something like link fragmentation and interleaving). Thank you Mohammad Salbad _______________________________________________ juniper-nsp mailing list juniper-nsp@puck.nether.net https://puck.nether.net/mailman/listinfo/juniper-nsp _______________________________________________ juniper-nsp mailing list juniper-nsp@puck.nether.net https://puck.nether.net/mailman/listinfo/juniper-nsp