[lug] Re: Help
Jason Davis
mohadib at openactive.org
Wed Oct 6 10:57:40 MDT 2004
hello,
If you want to learn about networking i would suggest getting a few
cheap/old machines to play with. Then , I would get a Linux book and
first try to set up SMB file sharing and NFS. This should give you a
working knowelege of networking and how to troubleshoot ... network
issues.
The things that i feel made me good at networking are...
1.Playing with iptables ... write a singel client firewall and a NATing
multi-client firewall
2. If you have dsl , buy a domain name and host the web and dns
at your house. This will teach soooo much!
3.Play with tcpdump,snort,ethereal .... good stuff
4. if you have a roomate and dsl ... try to route yourself out the dsl ,
then while still connected to the DSL , dial up on the same line
and route your roomate out of the dial up ... this will teach you
basic static routing....and its fun
good luck,
jd
On Tue, 2004-10-05 at 21:42, vinatha.komirishetty at wipro.com wrote:
> Hi,
> I have been reading the mails with queries that are been posted
> to this list.im much intrested in networking concepts with linux as
> OS..cud any one of u guide me in knowing them..from the scratch (ie
> basics)...i have some basic idea that I have learnt in my UG..
>
> Thanks & Regards,
> Vinatha.
>
>
>
> -----Original Message-----
> From: lug-bounces at lug.boulder.co.us
> [mailto:lug-bounces at lug.boulder.co.us] On Behalf Of Michael Deck
> Sent: Monday, October 04, 2004 10:45 PM
> To: mohadib at openactive.org; Boulder (Colorado) Linux Users Group --
> General Mailing List; Boulder (Colorado) Linux Users Group -- General
> Mailing List
> Subject: Re: [lug] DNS Problems: Is it me, or is it Comcast?
>
> 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.
> > >
> > > _______________________________________________
> > > Web Page: http://lug.boulder.co.us
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> > > Join us on IRC: lug.boulder.co.us port=6667 channel=#colug
> >
> >_______________________________________________
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>
>
> Michael Deck
> Cleanroom Software Engineering, Inc.
>
> _______________________________________________
> Web Page: http://lug.boulder.co.us
> Mailing List: http://lists.lug.boulder.co.us/mailman/listinfo/lug
> Join us on IRC: lug.boulder.co.us port=6667 channel=#colug
>
>
>
>
>
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