[73221] in North American Network Operators' Group

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Re: Summary with further Question: Domain Name System protection

daemon@ATHENA.MIT.EDU (bmanning@vacation.karoshi.com)
Mon Aug 16 23:57:51 2004

Date: Tue, 17 Aug 2004 03:57:17 +0000
From: bmanning@vacation.karoshi.com
To: Joe Shen <joe_hznm@yahoo.com.sg>
Cc: Bill Woodcock <woody@pch.net>, nanog@merit.edu
In-Reply-To: <20040817030304.26432.qmail@web90006.mail.scd.yahoo.com>
Errors-To: owner-nanog-outgoing@merit.edu


> 1. ISPs use firewall to protect their DNS server;

	some do, some don't

> 4. Anycast is the most scalable and standard solution
> for dispersed DNS server farm, while layer-4 switch
> could deal could do with centralized server farm;

	its not a standard.

> 5. 'bogon'in BIND configuration could be used to
> filter requests from RFC1918 address;

	this should be pushed to
	the router.  don't waste CPU cycles 
	on the Nameserver.

> 6. Firewall may become bottleneck of DNS server farm
> in situation of DoS attack or situation of high
> session rate;

	yes

> 7. It's good solution to divide DNS servers into two
> groups, one for recursive lookup the other for
> no-recuresive;

	yes

> 8. BIND should be configured carefully and there is
> BIND secure template to follow

	altho the template will not meet every case.

> a) If firewall is used to protect DNS server farm,
> could it do more than router's ACL while reaching the
> same performance-cost ratio ? which one is usually
> chosen by those ISPs having big customer numbers? (we
> noticed DNS requests from our customers keep increase
> in past months) 

	general rule - drop undesired traffic as far
	upstream as possible.

> b) Is there any public available performance
> evaluation on Nominum's product? 

	you should check w/ the Nominum staff on any
	performance evaluations.

> 
> Any of your words will be highly appreciated.
> 
> Joe
> 
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