North American Network Operators Group Date Prev | Date Next | Date Index | Thread Index | Author Index | Historical Re: Seeking Comcast Contact: need to troubleshoot packet loss and/or asymmetric routing issue between Comcast & Onvoy
On 8/2/07, [email protected] <[email protected]
> wrote:
AIX 5.3 changes the whole PMTU scheme to work more like the RFCs and not depend on out of band ICMP packets. From http://www.ibm.com/developerworks/aix/library/au-aix5l-me.html : PMTU discovery in AIX 5L Version 5.3 The current Path Maximum Transmission Unit (PMTU) discovery implementation uses ICMP Echo Request and ICMP Echo Reply packets to discover PMTU. Some system administrators set up their firewall to drop ICMP Echo packets, resulting in the above method of PMTU discovery to fail. The PMTU discovery mechanism in AIX 5L Version 5.3 is implemented with TCP packets and UDP datagram instead of ICMP Echo packets.
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