nanog mailing list archives
Re: Consumer networking head scratcher
From: Roland Dobbins <rdobbins () arbor net>
Date: Thu, 2 Mar 2017 12:24:38 +0700
On 2 Mar 2017, at 9:55, Oliver O'Boyle wrote:
Currently, I have 3 devices connected. :)
You could have one or more botted machines launching outbound DDoS attacks, potentially filling up the NAT translation table and/or getting squelched by your broadband access provider with layer-4 granularity. And the boxes themselves could be churning away due to being compromised (look at CPU and memory stats over time). Aggressive horizontal scanning is often a hallmark of botted machines, and it can interrupt normal network access on the botted hosts themselves.
I don't actually think that's the case, given the symptomology you report, but just wanted to put it out there for the list archive.
What about DNS issues? Are you sure that you really have a networking issue, or are you having intermittent DNS resolution problems caused by flaky/overloaded/attacked recursivs, EDNS0 problems (i.e., filtering on DNS responses > 512 bytes), or TCP/53 blockage? Different host OSes/browsers/apps exhibit differing re-query characteristics. Are the Windows boxes and the other boxes set to use the same recursors? Can you resolve DNS requests during the outages?
Are your boxes statically-addressed, or are they using DHCP? Periodically-duplicate IPs can cause intermittent symptoms, too. If you're using the consumer router as a DHCP server, DHCP-lease nonsense could be a contributing factor.
Are the Windows boxes running some common application/service which updates and/or churns periodically? Are they members of a Windows workgroup? All kinds of strange name-resolution stuff goes on with Windows-specific networking.
Also, be sure to use -n with traceroute. tcptraceroute is useful, too. netstat -rn should work on Windows boxes, IIRC.
----------------------------------- Roland Dobbins <rdobbins () arbor net>
Current thread:
- Re: Consumer networking head scratcher, (continued)
- Re: Consumer networking head scratcher iamzam () gmail com (Mar 01)
- RE: Consumer networking head scratcher Aaron Gould (Mar 02)
- Re: Consumer networking head scratcher David Bass (Mar 02)
- RE: Consumer networking head scratcher Dann Schuler (Mar 02)
- Re: Consumer networking head scratcher Mark Wiater (Mar 02)
- Re: Consumer networking head scratcher Ryan Pugatch (Mar 01)
- Re: Consumer networking head scratcher Ryan Pugatch (Mar 01)
- Re: Consumer networking head scratcher Oliver O'Boyle (Mar 01)
- Re: Consumer networking head scratcher Ryan Pugatch (Mar 01)
- Re: Consumer networking head scratcher Oliver O'Boyle (Mar 01)
- Re: Consumer networking head scratcher Oliver O'Boyle (Mar 01)
- Re: Consumer networking head scratcher Roland Dobbins (Mar 01)
- Re: Consumer networking head scratcher Chuck Anderson (Mar 01)
- RE: Consumer networking head scratcher Aaron Gould (Mar 02)
- Re: Consumer networking head scratcher Ryan Pugatch (Mar 02)
- Re: Consumer networking head scratcher Roland Dobbins (Mar 01)
- Re: Consumer networking head scratcher Ryan Pugatch (Mar 02)