Date: Sat, 11 May 2019 21:52:55 +0000 From: bugzilla-noreply@freebsd.org To: bugs@FreeBSD.org Subject: [Bug 237843] arp skips all name lookups if first fall with TRY_AGAIN Message-ID: <bug-237843-227@https.bugs.freebsd.org/bugzilla/>
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https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D237843 Bug ID: 237843 Summary: arp skips all name lookups if first fall with TRY_AGAIN Product: Base System Version: 12.0-STABLE Hardware: Any OS: Any Status: New Severity: Affects Only Me Priority: --- Component: bin Assignee: bugs@FreeBSD.org Reporter: pete@twisted.org.uk This appears to be deliberate, but I am not sure the actual outcome is as intended. My arp table looks like this: [pete@skerry /usr/src/usr.sbin/arp]$ arp -a ? (82.47.240.1) at 00:01:5c:73:86:47 on bge1 expires in 1199 seconds [ether= net] ? (82.47.240.30) at d0:bf:9c:45:8b:71 on bge1 permanent [ethernet] ? (192.168.3.42) at 60:6d:3c:07:8c:2c on bge0 expires in 1142 seconds [ethernet] ? (192.168.3.201) at d0:bf:9c:45:8b:70 on bge0 permanent [ethernet] ? (192.168.3.200) at d0:bf:9c:45:8b:70 on bge0 permanent [ethernet] all of the 192.168 addresses will resolve, but because the first one (and possibly the second one) do not, then it need tries to look them up. removi= ng the line which sets 'nflag' to 1 after a TRY_AGAIN results in this. [pete@skerry ~]$ ./a.out -a=20 ? (82.47.240.1) at 00:01:5c:73:86:47 on bge1 expires in 1198 seconds [ether= net] ? (82.47.240.30) at d0:bf:9c:45:8b:71 on bge1 permanent [ethernet] fire-tv.drayhouse.twisted.org.uk (192.168.3.42) at 60:6d:3c:07:8c:2c on bge0 expires in 1126 seconds [ethernet] skerry-ns.drayhouse.twisted.org.uk (192.168.3.201) at d0:bf:9c:45:8b:70 on = bge0 permanent [ethernet] skerry.drayhouse.twisted.org.uk (192.168.3.200) at d0:bf:9c:45:8b:70 on bge0 permanent [ethernet] madeira.drayhouse.twisted.org.uk (192.168.3.47) at 08:f4:ab:00:5f:86 on bge0 expires in 1183 seconds [ethernet] Which is far more useful - I;ve trimmed the output there, there are a lot of machines on the local LAN, and arp always used to be an easy way to see what was connected by name. its behaviour hasn't changed, but the presence of the unresolvable 82. address has stopped it resolving the rest. I assume the intent was to stop trying slow lookups that always failed, but= the actual end result is that it won't look up any names. Not sure how to fix t= his - would the simple, approach of not giving up name lookups be unacceptable ? Probably a better fix would be to disable lookups which are for addresses n= ot on any local LAN, but that is a lot more complex, and maybe outside the sco= pe of what arp should be doing. But having a way to get a list of name lookups on the local LAN wold be very useful, which is what I am really after here. --=20 You are receiving this mail because: You are the assignee for the bug.=
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