Possible IP fragmentation issue
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Description
I'm using the Cisco 3725 model in GNS3. I observed an odd behavior with IP fragmentation when experimenting with randomly generated IP datagrams. The input to the router was a fragmented datagram with these fields:
more = 0
don't fragment = 1
offset = 1
The forwarded datagram had these fields:
more = 0
don't fragment = 1
offset = 0
In other words, the fragment was converted to a whole datagram with only part of the data.
Arguably the input datagram should never have been sent. My question, though, is whether this behavior accurately reflects the behavior of the actual Cisco hardware, or whether it is an artifact of the model.
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Research direction
Start by reproducing the reported case in the Cisco 3725 model using a fragmented datagram with more=0, don't fragment=1, and offset=1. Trace the forwarded datagram's flags, offset, and payload, then compare the result with documented or observed Cisco hardware behavior. Done means determining whether the discrepancy is expected hardware behavior or an emulator defect.
Written by the indexing model from the issue text.
Assessment
- Domain
- networking
- Issue type
- Bug
- Difficulty
- 4/5
- Estimated time
- 3-5 days
- Activity status
- Stale
- Clarity
- Needs clarification
- Newbie friendliness
- 25/100