06-15-2008 12:39 AM
Dear Experts ,
I'm trying to run MPLS between two 7206 vxr router which is connected behind a Foundry Big Iron L3 router which is configured as a L2 device .
I put on my 7206 as
int gi0/1
ip address 172.16.14.1 255.255.255.0
mpls ip
mpls mtu 1526
But it seems that there is tag assiging ,but traffic like https didn't work after that . is there is any clue ?
Regards
Haris
06-15-2008 06:07 AM
HI Haris, [Pls Rate if HELPS]
I beleive if your Interface @ Gi0/1 of 7206 is configured by any one way as below means it should work:
Option: I
MPLS-Router#sh run int Gi0/2
Building configuration...
Current configuration : 217 bytes
!
interface GigabitEthernet0/2
description TO SWITCH xxx.xxx.xxx.xxx
mtu 1526
no ip address
no ip mroute-cache
load-interval 30
duplex full
speed 1000
media-type rj45
no negotiation auto
no cdp enable
end
Option: II
MPLS-Router#sh run int Gi0/1
Building configuration...
Current configuration : 329 bytes
!
interface GigabitEthernet0/1
description to SWITCH
mtu 1526
ip address xxx.xxx.xxx.xx xxx.xxx.xxx.xx
ip route-cache flow
load-interval 30
duplex full
speed 100
media-type rj45
no negotiation auto
mpls label protocol ldp
tag-switching ip
end
Try to Increase the MTU size on SWITCH and see the possibility to enable the Jumbo Frame Option if applicable.
Check the same and Kindly Update. Hope i am Informaitve.
Pls RATE if HELPS
Best Regards,
Guru Prasad R
06-15-2008 06:16 AM
Haris,
I suppose the default MTU of 1518 on the Foundry device includes the ethernet header and checksum, which leaves 1500 bytes for the payload. This is not sufficient to carry 1500 bytes IP packets + the mpls label(s). Try increasing the MTU on the Big Iron.
Regards,
06-15-2008 09:43 PM
Hi ,
There is no way to increase the MTU size on foundry . But it's giving me some error
BigIron1(config-if-e1000-1/8)#ip mtu 1526
Error - 1526 not between 576 and 1500
BigIron1(config-if-e1000-1/8)#mtu ?
Unrecognized command
How can know that whether the foundry supporting giant packets / not ? . I think it's not supporting giants , the following is the output of ping sweep from one cisco router to other one .
If it's not supporting giants what will happens to my mpls packets with size 1508 ? . Is it possible me to put the command "mpls mtu 1500" ,so that mpls mtu will limit to 1500
router1#ping
Protocol [ip]:
Target IP address: 213.12.90.1
Repeat count [5]: 1
Extended commands [n]: y
Source address or interface: 213.12.83.137
Set DF bit in IP header? [no]: y
Sweep range of sizes [n]: y
Sweep min size [36]: 1450
Sweep max size [18024]: 1550
Sweep interval [1]:
Type escape sequence to abort.
Sending 101, [1450..1550]-byte ICMP Echos to 213.12.90.1, timeout is 2 seconds:
Packet sent with a source address of 213.12.83.137
Packet sent with the DF bit set
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!.!!!!!!!.......................
...............................
Success rate is 45 percent (46/101), round-trip min/avg/max = 20/44/120 ms
the ping is same with and without DF bit set after enabling MPLS . But before enabling tag switching as I remember I was able to ping without DF Bit set
Regards
Haris
06-16-2008 06:36 AM
Haris,
I would be very surprised if te BigIron didn't support jumbo frames. You should check for a command in global mode (not at the interface level) to enable jumbo frame support.
Regards,
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