[lug] DNS Problems: Is it me, or is it Comcast?

[Michael Deck]

Jason, thanks. That is a really useful tool. I used its advice to tidy up 
my zone files. Nothing there to suggest anything super bad, but you never 
know what Comcast thinks is bad, I guess.

At 09:52 AM 10/4/2004, Jason Davis wrote:


>http://www.dnsreport.com/tools/dnsreport.ch?domain=cleansoft.com
>
>On Mon, 2004-10-04 at 09:33, Michael Deck wrote:
> > I started having some DNS problems on Friday morning, and I need help
> > determining whether it's in the name server that I administer, or whether
> > it's entirely a Comcast problem (and what I might suggest they do about 
> it).
> >
> > Here are the details. On Friday morning I noticed I was unable to ping my
> > remote server (cleansoft.com) by name but I could ping it by IP address
> > (198.49.126.122). This from my home office, which has Comcast "business"
> > cable internet. The remote host is running KRUD FC1 and is authoritative
> > for cleansoft.com.
> >
> > I also noticed I could ping the server by name from the host of one of my
> > clients. At first I thought that this was a DNS refresh problem, or maybe
> > an iptables problem, but I think I've convinced myself it isn't iptables.
> >
> > If I put 198.49.126.122 in /etc/resolv.conf as a nameserver, my local
> > problems go away. Emails appear to be reaching me from everywhere except
> > other comcast users.
> >
> > What I don't know is whether my zone files are somehow causing the 
> problem.
> > Here is another tidbit that worries me. When I use
> >
> >    host -v -C cleansoft.com
> >
> > from my client's system,
> >
> >   > host -v -C cleansoft.com
> >   Trying "cleansoft.com"
> >   Received 121 bytes from xxx.xx.xxx.x#53 in 7 ms
> >   Trying "cleansoft.com"
> >   ;; connection timed out; no servers could be reached
> >
> > where I've blunked out my client's DNS host address. So what does this
> > mean? I thought -C meant to try to find the authoritative nameserver.
> >
> > Here is my zone file for cleansoft.com. Note, this setup has been working
> > for a couple of months until Friday morning, and I haven't changed 
> anything
> > related to BIND that I am aware of, though there may have been a system
> > reboot in there that I don't know about. I checked my record with my 
> domain
> > registrar, and it shows ns1.cleansoft.com 198.49.126.122 as primary
> > nameserver for this domain.
> >
> > cleansoft.com.  IN SOA  ns1.cleansoft.com. postmaster.cleansoft.com. (
> >                                  6       ; Serial
> >                                  10800   ; Refresh after 3 hours
> >                                  3600    ; Retry after 1 hour
> >                                  604800  ; Expire after 1 week
> >                                  86400   ; Minimum TTL of 1 day
> > )
> >
> > cleansoft.com.  IN NS   ns1.cleansoft.com.
> > cleansoft.com.  IN NS   ns2.cleansoft.com.
> >
> > ;
> > ; Host addresses
> > ;
> >
> > localhost.cleansoft.com.        IN A    127.0.0.1
> > www.cleansoft.com.              IN A    198.49.126.122
> > cleansoft.com.                  IN A    198.49.126.122
> > mail.cleansoft.com.             IN A    198.49.126.122
> > ns1.cleansoft.com.              IN A    198.49.126.122
> > ns2.cleansoft.com.              IN A    198.49.126.122
> > cleansoft.com.                  IN MX   0 cleansoft.com.
> >
> >
> >
> > Michael Deck
> > Cleanroom Software Engineering, Inc.
> >
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Michael Deck
Cleanroom Software Engineering, Inc.