limiting number of requests of a single hosts

2012-06-15 Thread Holemans Wim
We have a problem with one of our firewalls caused by DNS peaks. Once or twice a day a DNS burst (20K requests/15sec) kills all connections on the firewall. The firewall is due for replacement but in the mean time we would like to stop these peaks at their origin or at least try to limit their

Re: limiting number of requests of a single hosts

2012-06-15 Thread Tony Finch
Holemans Wim wim.holem...@ua.ac.be wrote: I have 2 questions, one, is there a way  to rate-limit the amount of request a single client (the AD servers in this case) can have standing out against a bind server ? Kind of rate-limiting parameter for bind name server. There isn't a way to do

Re: limiting number of requests of a single hosts

2012-06-15 Thread WBrown
bind-users-bounces+wbrown=e1b@lists.isc.org wrote on 06/15/2012 04:25:16 AM: We have a problem with one of our firewalls caused by DNS peaks. Once or twice a day a DNS burst (20K requests/15sec) kills all connections on the firewall. The firewall is due for replacement but in the mean

RE: limiting number of requests of a single hosts

2012-06-15 Thread Holemans Wim
Wim Holemans Netwerkdienst Universiteit Antwerpen Network Services University of Antwerp One of the problems is that these firewalls are going to be replaced soon and we don't want to spend to much effort in trying to fix what seems an annoying side-effect of something caused by a DNS

Re: limiting number of requests of a single hosts

2012-06-15 Thread Fajar A. Nugraha
On Fri, Jun 15, 2012 at 9:37 PM, Holemans Wim wim.holem...@ua.ac.be wrote: Wim Holemans Netwerkdienst Universiteit Antwerpen Network Services University of Antwerp One of the problems is that these firewalls are going to be replaced soon and we don't want to spend to much effort in

RE: limiting number of requests of a single hosts

2012-06-15 Thread Holemans Wim
Universiteit Antwerpen Network Services University of Antwerp -Original Message- From: Fajar A. Nugraha [mailto:w...@fajar.net] Sent: vrijdag 15 juni 2012 17:02 To: Holemans Wim Cc: bind-users@lists.isc.org Subject: Re: limiting number of requests of a single hosts On Fri, Jun 15, 2012 at 9:37 PM

Re: limiting number of requests of a single hosts

2012-06-15 Thread pangj
You DO realize that DNS is (mostly) UDP packets, and an attacker (or in your case, the ADs) can simply send UDP packet floods to kill your firewall (in your current state), regardless how your DNS server is configured, even when the DNS server is down? Once we had the firewall for DNS, when

Re: limiting number of requests of a single hosts

2012-06-15 Thread Warren Kumari
On Jun 15, 2012, at 4:25 AM, Holemans Wim wrote: We have a problem with one of our firewalls caused by DNS peaks. Yes. EOM W Once or twice a day a DNS burst (20K requests/15sec) kills all connections on the firewall. The firewall is due for replacement but in the mean time we would like

Re: limiting number of requests of a single hosts

2012-06-15 Thread G.W. Haywood
Hi there, On Fri, 15 Jun 2012, Holemans Wim wrote: ... Once or twice a day a DNS burst (20K requests/15sec) kills all connections on the firewall. Have you disabled firewall connection tracking for DNS requests? We have 6 dns servers (bind) on our campus, that are all authoritative for our

Re: limiting number of requests of a single hosts

2012-06-15 Thread Sten Carlsen
On 15/06/12 16:37, Holemans Wim wrote: Wim Holemans Netwerkdienst Universiteit Antwerpen Network Services University of Antwerp One of the problems is that these firewalls are going to be replaced soon and we don't want to spend to much effort in trying to fix what seems an annoying