I’ve been troubleshooting some pretty large networks lately, and since DNS underpins most enterprise networks it’s very useful to see what traffic is going through the DNS servers. By default Ubuntu doesn’t log every query, and I can understand why. The average home network generates 100’s of DNS queries an hour, enterprise networks generate magnitudes of scale more.
All posts tagged dns
I’ve been working with some small businesses, and it makes life a heck of a lot easier for everyone all round if people use sensible DNS names when setting things up. I’ve looked around and can’t find any suggested best practice, so please see below my suggestions based on all my years experience… If anyone can point me to any other best practice I’ll be a very happy guy!
- remote.companya.com – This record should be the IP address of the static IP of the main internet connection. If applicable allow RDP or SSH.
- mail.companya.com – If the company is hosting their own SMTP flow this can be the MX record, it should also be used for OWA and the like. If the company is sending out email from this address clean onto the internet it will make sense to have the rDNS as mail.companya.com also.
It seems that something as critical as email for the business environment should be protected at all costs, and that too goes for making any changes to said email servers. Especially when the nature of email is that it can take up to 48 hours for any mistakes you make to a internet facing infrastructure to propagate themselves out. So knowing what you are doing is vital.