The MPLS-OPS Archive[Date Prev][Date Next][Thread Prev][Thread Next] [Date Index][Thread Index][Author Index][Subject Index] Re: Fragmentation in MPLS network BGP problem
Robert, See my pings bellow: For ICMP 1500 ok for 2000 it fails. The 1500 ping... PE01#ping Protocol [ip]: Target IP address: pe02 (loopback address) Repeat count [5]: Datagram size [100]: 1500 Timeout in seconds [2]: Extended commands [n]: y Source address or interface: pe01 (loopback address) Type of service [0]: Set DF bit in IP header? [no]: Validate reply data? [no]: Data pattern [0xABCD]: Loose, Strict, Record, Timestamp, Verbose[none]: Sweep range of sizes [n]: Type escape sequence to abort. Sending 5, 1500-byte ICMP Echos to 10.190.107.251, timeout is 2 seconds: !!!!! Success rate is 100 percent (5/5), round-trip min/avg/max = 1/2/4 ms PE01# 04:45:01: IP: s=10.190.107.252 (local), d=10.190.107.251, len 1500, cef process switched 04:45:01: ICMP type=8, code=0 04:45:01: IP: s=10.190.107.252 (local), d=10.190.107.251, len 1500, cef process switched 04:45:01: ICMP type=8, code=0 04:45:01: IP: s=10.190.107.251 (FastEthernet12/0/0), d=10.190.107.252, len 1500, rcvd 4 04:45:01: ICMP type=0, code=0 04:45:01: IP: s=10.190.107.252 (local), d=10.190.107.251, len 1500, cef process switched 04:45:01: ICMP type=8, code=0 04:45:01: IP: s=10.190.107.252 (local), d=10.190.107.251, len 1500, cef process switched 04:45:01: ICMP type=8, code=0 04:45:01: IP: s=10.190.107.251 (FastEthernet12/0/0), d=10.190.107.252, len 1500, rcvd 4 04:45:01: ICMP type=0, code=0 04:45:01: IP: s=10.190.107.252 (local), d=10.190.107.251, len 1500, cef process switched 04:45:01: ICMP type=8, code=0 04:45:01: IP: s=10.190.107.252 (local), d=10.190.107.251, len 1500, cef process switched 04:45:01: ICMP type=8, code=0 04:45:01: IP: s=10.190.107.251 (FastEthernet12/0/0), d=10.190.107.252, len 1500, rcvd 4 04:45:01: ICMP type=0, code=0 04:45:01: IP: s=10.190.107.252 (local), d=10.190.107.251, len 1500, cef process switched 04:45:01: ICMP type=8, code=0 04:45:01: IP: s=10.190.107.252 (local), d=10.190.107.251 PE01#, len 1500, cef process switched 04:45:01: ICMP type=8, code=0 04:45:01: IP: s=10.190.107.251 (FastEthernet12/0/0), d=10.190.107.252, len 1500, rcvd 4 04:45:01: ICMP type=0, code=0 04:45:01: IP: s=10.190.107.252 (local), d=10.190.107.251, len 1500, cef process switched 04:45:01: ICMP type=8, code=0 04:45:01: IP: s=10.190.107.252 (local), d=10.190.107.251, len 1500, cef process switched 04:45:01: ICMP type=8, code=0 04:45:01: IP: s=10.190.107.251 (FastEthernet12/0/0), d=10.190.107.252, len 1500, rcvd 4 04:45:01: ICMP type=0, code=0 PE01# The 2000 ping... PE01#ping Protocol [ip]: Target IP address: pe02 Repeat count [5]: Datagram size [100]: 2000 Timeout in seconds [2]: Extended commands [n]: y Source address or interface: pe01 Type of service [0]: Set DF bit in IP header? [no]: Validate reply data? [no]: Data pattern [0xABCD]: Loose, Strict, Record, Timestamp, Verbose[none]: Sweep range of sizes [n]: Type escape sequence to abort. Sending 5, 2000-byte ICMP Echos to 10.190.107.251, timeout is 2 seconds: ..... Success rate is 0 percent (0/5) PE01# 05:00:51: IP: s=10.190.107.252 (local), d=10.190.107.251, len 2000, cef process switched 05:00:51: ICMP type=8, code=0 05:00:51: IP: s=10.190.107.252 (local), d=10.190.107.251, len 2000, cef process switched 05:00:51: ICMP type=8, code=0 05:00:51: IP: s=10.190.107.251 (FastEthernet12/0/0), d=10.190.107.252, len 504, rcvd 4 05:00:51: IP Fragment, Ident = 46, fragment offset = 1496 05:00:51: IP: recv fragment from 10.190.107.251 offset 1496 bytes 05:00:53: IP: s=10.190.107.252 (local), d=10.190.107.251, len 2000, cef process switched 05:00:53: ICMP type=8, code=0 05:00:53: IP: s=10.190.107.252 (local), d=10.190.107.251, len 2000, cef process switched 05:00:53: ICMP type=8, code=0 05:00:53: IP: s=10.190.107.251 (FastEthernet12/0/0), d=10.190.107.252, len 504, rcvd 4 05:00:53: IP Fragment, Ident = 47, fragment offset = 1496 05:00:53: IP: recv fragment from 10.190.107.251 offset 1496 bytes 05:00:55: IP: s=10.190.107.252 (local), d=10.190.107.251, len 2000, cef process switched 05:00:55: ICMP type=8, code=0 05:00:55: IP: s=10.190.107.252 (local), d=10.190.107.251, len 2000, cef process switched 05:00:55: ICMP type=8, code=0 05:00:55: IP: s=10.190.107.251 (FastEthernet12/0/0), d=10.190.107.252, len 504, rcvd 4 05:00:55: IP Fragment, Ident = 48, fragment offset = 1496 05:00:55: IP: recv fragment from 10.190.107.251 offset 1496 bytes 05:00:57: IP: s=10.190.107.252 (local), d=10.190.107.251, len 2000, cef process switched 05:00:57: ICMP type=8, code=0 05:00:57: IP: s=10.190.107.252 (local), d=10.190.107.251, len 2000, cef process switched 05:00:57: ICMP type=8, code=0 05:00:57: IP: s=10.190.107.251 (FastEthernet12/0/0), d=10.190.107.252, len 504, rcvd 4 05:00:57: IP Fragment, Ident = 49, fragment offset = 1496 05:00:57: IP: recv fragment from 10.190.107.251 offset 1496 bytes 05:00:59: IP: s=10.190.107.252 (local), d=10.190.107.251, len 2000, cef process switched 05:00:59: ICMP type=8, code=0 05:00:59: IP: s=10.190.107.252 (local), d=10.190.107.251, len 2000, cef process switched 05:00:59: ICMP type=8, code=0 05:00:59: IP: s=10.190.107.251 (FastEthernet12/0/0), d=10.190.107.252, len 504, rcvd 4 05:00:59: IP Fragment, Ident = 50, fragment offset = 1496 05:00:59: IP: recv fragment from 10.190.107.251 offset 1496 bytes PE01# Any light? Thanks, Marcelo. On Sun, 21 Oct 2001, Robert Raszuk wrote: > Marcelo, > > > I have PE - P - PE router. If I do a ping in PE to PE if datagram size for > > example 2000 (PE to P router has ether interface if tag mut 1526) with DF > > bit not set, I got I timeout answer. For 1500 it work fine. > > You would need to narrows down where your packets are being lost. Maybe > you have a bug of not bumping to process switching (some platforms like > GSR don't support that at all), > > > Ok Robert, but iBGP messages ( session VPNv4 ) is exchange between > > loopacks. Will iBGP looks to MTU in the loopback?! > > No it does not matter what it the IBGP update-src or dst. It matters via > what PHYSICAL interface the packets are going out of your router, IBGP > is not aware about any MTU issue. It just passed the generated updates > to TCP/IP stack and all fragmentatation is done there. > > R. > > ------- > The MPLS-OPS Mailing List > Subscribe/Unsubscribe: http://www.mplsrc.com/mplsops.shtml > Archive: http://www.mplsrc.com/mpls-ops_archive.shtml > ------- The MPLS-OPS Mailing List Subscribe/Unsubscribe: http://www.mplsrc.com/mplsops.shtml Archive: http://www.mplsrc.com/mpls-ops_archive.shtml
|
|