Bug 2156751

Summary: systemd-resolved sends icmp port unreachable to the slowest upstreams
Product: Red Hat Enterprise Linux 8 Reporter: Ravindra Patil <ravpatil>
Component: systemdAssignee: David Tardon <dtardon>
Status: VERIFIED --- QA Contact: Frantisek Sumsal <fsumsal>
Severity: unspecified Docs Contact:
Priority: unspecified    
Version: 8.6CC: aperotti, apmukher, dtardon, elia.pinto, fkrska, fperalta, jamacku, systemd-maint-list, systemd-maint
Target Milestone: rcKeywords: Improvement, Triaged, VerifiedUpstream
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Hardware: Unspecified   
OS: Unspecified   
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Fixed In Version: systemd-239-77.el8 Doc Type: If docs needed, set a value
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Description Ravindra Patil 2022-12-28 14:09:46 UTC 
Description of problem:
When using systemd-resolved, it reports ICMP port as unreachable. 

Version-Release number of selected component (if applicable):
systemd-239-58.el8_6.8.x86_64

How reproducible:
Query ICMP on system which is using systemd-resolved. 

Steps to Reproduce:
1. Use systemd-resolved for local name resolution
2. Send ICMP queries locally 


Actual results:
- systemd-resolved sends queries to nameservers (UDP to port upstream:53)
- answers are ignored (UDP from upstream:53)
- kernel sends ICMP port unreachable

Expected results:
- systemd-resolved sends queries to nameservers (UDP to port upstream:53)
- answers are read (UDP from upstream:53)


Additional info:

The issue has been fixed in upstream. 

https://github.com/systemd/systemd/issues/17421
Comment 8 Plumber Bot 2023-06-14 16:02:55 UTC 
fix merged to github main branch -> https://github.com/redhat-plumbers/systemd-rhel8/pull/380