Messages in this thread | | | From | "Song, Xiongwei" <> | Subject | RE: Response error to fragmented ICMP echo request | Date | Wed, 8 Mar 2023 06:00:26 +0000 |
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Hi Vladimir,
> On Tue, Mar 07, 2023 at 12:56:17PM +0000, Song, Xiongwei wrote: > > > Frames 3 and 4 are sent with DEI=1 and are dropped, frames 1 and 2 are > > > sent with DEI=0 and are not dropped. I'm not sure if varying the DEI > > > field is part of the intentions of the test? Is there any RFC which says > > > that IP fragments over VLAN should use DEI=1, or some other reason? > > > > I didn't notice that. Let me check the test why set DEI=1. > > Ok. It would be good to have an answer to this, because one of the > assumptions of that patch was that whomever sets DEI=1 doesn't get to > complain that their packets are *actually* dropped :)
We found the problem in the test: ===================== f2=Ether(src="26:84:d5:7f:7d:be", dst="7C:72:6E:D4:44:C1")/Dot1Q(prio=0, vlan=984)/IP(src="10.225.32.20", dst="10.225.32.21")/'\x00\x00\x00\x00\x00\x00\x00\x00' f2.frag=1 ===>f2.id=1 f2.proto='icmp' // result of f2.show() ###[ Ethernet ]### dst = 7C:72:6E:D4:44:C1 src = 26:84:d5:7f:7d:be type = 0x8100 ###[ 802.1Q ]### prio = 0 id = 1 vlan = 984 type = 0x800 ###[ IP ]### version = 4 ihl = None tos = 0x0 len = None id = 1 flags = frag = 1 ttl = 64 proto = icmp chksum = None src = 10.225.32.20 dst = 10.225.32.21 \options \ ###[ Raw ]### load = '\x00\x00\x00\x00\x00\x00\x00\x00' ================= This sets both the L2 & L3 id. L2 id is actually DEI. We updated the script to only set L3 id and now the test passes.
> > FWIW, if you do need to set up a reservation for traffic received on a > port, section 8.6.3.3.15 Buffer reservation watermarks (page 817) should > help with this: > https://www.nxp.com/docs/en/user-guide/LLDPUG_RevL5.15.71-2.2.0.pdf
Thank you so much. We don't need to set up a reservation for now, but good to know this.
Regards, Xiongwei
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