Greeblesnort
  • Member for 12 years, 7 months
  • Last seen more than 9 years ago
SOA and Primary NS record (DNS)
11 votes

Nameserver records are specified in your zone file. The SOA record indicates the primary nameserver for the zone. There is no automatic relationship between the two. Here is a good read regarding SOA ...

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Getting stats about deliverability from postfix
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7 votes

I have been using pflogsumm for about 5 or 6 years. It should be readily available via apt-get or yum. Normally, I'll check the report at least once a week just to make sure the numbers look normal, ...

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Can an IP address in the private range be used as a public address?
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6 votes

Any IP can be routed. But a network admin or an ISP that's worth their salt will block the egress/ingress of packets sourced from or destined for those addresses at the edge of their network. There ...

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How to configure postfix to pipe all incoming email to a script?
5 votes

The only time I've used something like this was for a specific user's mailbox. All that was required was to alias that user's name to a pipe and a process in aliases: pong: "| /usr/local/bin/gotit....

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BIND authoritative name server: SERVFAIL?
4 votes

You can turn up debugging to see if that doesn't directly answer your question. However, I'd suspect that the permissions on your zone file aren't allowing the bind user to read the file. I define ...

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Setting spanning tree link "priorities" in Cisco switches
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4 votes

If I understand your OP correctly, you're talking about running multiple links between switches and then specifying different VLANs per each link. This would be less than optimal. A more ideal ...

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Postfix Configuration problem (domain of sender address does not exist)
4 votes

This is one of those issues that you will need to involve/bribe/blackmail your DNS admin for assistance on as you will want the name your server claims when trying to send to be correct. Mnay servers ...

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Getting a feel for postfix
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3 votes

For my dollar, the postfix web site is very well documented. address re-writing security is somewhat addressed in the architecture overview: TLS and SASL are both addressed as well If you have ...

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Network port open, but no process attached?
3 votes

I actually wrote a small shell script to help id these occassional questions: #! /bin/bash ([ "$1" = "" ] || [ "$2" = "" ]) && echo "Usage: tracer <space> <port>" && exit ...

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Why is DNS failover not recommended?
2 votes

I've been using DNS based site-balancing and failover for the last ten years, and there are some issues, but those can be mitigated. BGP, while superior in some ways is not a 100% solution either with ...

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I need a server or service that reroutes DNS requests
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2 votes

We have a little more complicated setup, with a DEV, TEST, BETA, and PROD environment. I claim some extra crafty points for coming up with our solution, which allows the developers to initially build ...

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DNS (named) zone file loads correctly but does not resolve
2 votes

Have you created the zone in your named.conf file? i.e.: zone "resursecrestine.org" { type master; file "resursecrestine.org"; }; According to a dig +trace, it does resolve...and ...

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What i need to read in order to configure PowerDNS?
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2 votes

I really strongly suggest you picking up a solid understanding of DNS prior to doing this...

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DNS Round-robin failover and load balancing
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2 votes

because it's cheaper and easier than anycasting (BGP) and because it can be implemented entirely on your own hardware from a load-balancing standpoint, there's very little you can do about the browser ...

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Conditional DNS forwarding with named on Linux
2 votes

Can you operate as a slave for newdomain.com? i.e., do a full transfer?

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Getting postfix working? Getting error: "Recipient address rejected: Policy Rejection- Please try later.;"
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2 votes

you mention SPF and TXT records, but forward and reverse DNS need to be correct as well. edit: easiest way I know to test: dig -x +short `dig +short your.domain.com` This should return "your.domain....

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Linux security training?
2 votes

If you'd like to do some light reading beforehand, www.sans.org has some excellent whitepapers on securing linux.

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Host Header DNS Problem - Requires FlushDNS
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2 votes

An A record is a static reference unless you're allowing dynamic updates. The fact that a /flushdns seems to fix the problem is a bit of a puzzler, as all that command does is clear the cache. ...

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Adding mail header if postfix DNS based RBL (realtime black hole) check fails
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2 votes

Could you extend your custom parsing to programatically query the RBL in question and then handle the response? i.e., pass the sending address to the RBL, get response, add X- header. You'd probably ...

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Forwarding mail to alias in Postfix
2 votes

At first guess, I'd say that joschi is on the right track...what's your $myorigin? Or, perhaps the output of postconf -n?

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Network (firewall) architecture for a LARGE corporation
2 votes

It depends on what sort of services you're offering outside of your network as well as how much security you need in front of key services. If you've got an e-commerce site that ties into a database ...

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Rate limiting an internet connection per user
2 votes

what you're looking for is "traffic shaping" According to monowall's feature page, traffic shaping is a standard feature. I don't see an easy to find feature page for Smoothwall, but it's also highly ...

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How to read the number of pending requests in the TCP stack backlog under linux?
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2 votes

If I understand the question correctly, I believe you're referring to the Recv-Q and Send-Q numbers from netstat. If these numbers are not near zero, there is a high probability that there is either ...

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How Do I Debug An IMAP Problem?
2 votes

I would also suggest that this is a postfix issue, what is the output of: postconf -n and tail -n 50 /var/log/maillog (mail.log on ubuntu boxes)

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Best labeler for the server room?
2 votes

We use this one, largely because the contractors we hire to run our wire (roughly 15k runs so far), use them to do all of their labeling. It's nice because it outputs labels more suitable for wiring, ...

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Is there a free service to host failover pages?
Accepted answer
2 votes

What you're asking for is actually a function usually reserved for HA type setups (hardware load balancers, multiple servers, etc). To return a different DNS resolution, you would first have to ...

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When I have to administrate an existing Linux server what's the best way to check if it is secure?
2 votes

In addition to some of the very good responses here, check out http://www.sans.org/. They have some very good documents if you're willing to do a little reading to get a better comprehension of "...

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iptables management tools for large scale environment
2 votes

holy balls (keepin' the theme alive!) man...12,000 core rules? I'm assuming you've considered all the easy options like simply dropping the sets into CVS? Puppet or CFengine? Honestly, from the ...

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SMTP message rate control on Ubuntu 8.04, preferably with postfix
2 votes

Possibly interesting for your implementation: default_destination_concurrency_limit (default: 20) The default maximal number of parallel deliveries to the same destination. This is the default ...

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How do I measure disk thrashing on linux?
1 votes

Have you gone thru the manpage? man vmstat If you need historical information, I use kSar. It has the additional useful ability that it can be run on a remote machine and gather information directly ...

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