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I have a T1 coming into one of my offices now, I would like to do some hosting from some boxes on location. My rudimentary setup was to use my domain registrar to add A-records pointing towards my T1's IP (one of the 5 we get)

The A-record works but when I do a tracrt to that address it sees all kinds of weird stuff including what looks like reverse DNS entries from our ISP.

I would like to know what the proper steps are to setting up a system of this type. What is standard to setting up a line of this kind to be properly ready to handle outside world traffic.


Most of our high bandwidth material is in a data center, but we have some applications we would like to share on the T1.

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How you set up the networking is going to be influenced by what customer premise equipment you have... – jj33 Jun 16 '09 at 12:03
right now I simply have an RVS400 (simple linksys router) but I could move one of my multi-nic boxes to be the router. – agdunn Jun 16 '09 at 12:04
NM, I misread the question. I thought you said the traceroute wasn't working, not that it worked but the PTRs looked odd... – jj33 Jun 16 '09 at 13:18

The A-record works but when I do a tracrt to that address it sees all kinds of weird stuff including what looks like reverse DNS entries from our ISP.

There's two bits there, first, when you traceroute to an address you see the IPs and/or hostnames of (in theory) every router in the path, this includes the many at the various ISP's involved.

The wiki page has some background:

Second is the IPs of the hosts themselves, unless you have space assigned by an RIR (eg, ARIN, APNIC) that's from the ISP and you'll have to contact them to either have it delegated to you (/26 or larger is what I've seen, but anything smaller then /24 is a hack) or you request what you want.

Except for mail-sending systems proper reverse DNS isn't needed, it's nice and highly recomended but not needed. Even for mail systems you can do without it, just some sites will be more likely to consider you a spammer.

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This is pretty much the answer I was going to write. +1 – RobM Jun 16 '09 at 12:32
So how would I go about setting up a proper reverse DNS system? – agdunn Jun 16 '09 at 14:12
Contact your ISP and ask them to set up a reverse DNS entry for you. It has to be done by the entity that "owns" the IP block – Kevin Kuphal Jun 16 '09 at 16:44

in most cases you need to contact your ISP to change revdns for ips you get 'at the end' of T1. revdns is usually delegated to customer's name servers if they get whole /24 [ aka C class ] or more.

i can only tell about poland, sweden, uk and germany - in general: isp's change revdns upon request of customer, without much paper work, free of charge. usually within 1-2 days of time.

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But I would be needing to run a name server correct? I was asking for the whole picture... I have never run a nameserver before and am only slightly familiar with BIND – agdunn Jun 16 '09 at 12:02
@agbunn. if you dont have much experience with name server i'll suggest using dns service provided by company you bought domain for. usually it does not cost anything or costs next to nothing. in this way you'll get 'proper' redundant dns. otherwise you can run dns server in your office [ then you delegate to that dns server ] and another dns server at other location [ and you delegate there as well - you do it with NS records ]. one of servers would be master, another slave. – pQd Jun 16 '09 at 12:18

As a follow-on to the comments about reverse DNS, some ISPs (your T1 provider) may be willing to delegate reverse DNS for your IP netblock. This can be done with a technique called classless rDNS. Check out this Wikipedia article.

I set this up last week for my IP block and it went pretty smoothly. The most complicated thing will be communicating the right thing to your ISP and then figuring out the correct zone name for your DNS host (or server if yor're hosting it yourself).

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Oh, I should have mentioned that you can get info about who actually owns your IP block by using the whois command on a UNIX-like system: 'whois' will return this information, but may include a pointer to another whois server that you would query to get more detailed information: 'whois -h otherservername.domain -p otherserverport' – Clint Miller Jun 22 '09 at 20:13

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