AW: [Snort-users] snort filter

Erek Adams erek at ...577...
Wed Sep 26 13:57:02 EDT 2001


On Wed, 26 Sep 2001, Eduard Meiler wrote:

> the DSN ist not ours.

Hrm...  Something odd could be going on then.

> the rule for that is like here, so how I shloud change this ?
>
> alert UDP $EXTERNAL_NET 53 -> ?HOME_NET :1023 (msg:"MISC sourse port 53 to <
> 1024"; classtype bad-unknown; sid:515; rev:2;)

No.  You should never change a rule to remove 'lots of alerts' until you are
certain that it is a false positive.

Have a look at the packet payload and see what's up.  Use something like:

	snort -dvr 0915 at ...3615... host 192.168.7.200

That should decode all packets to/from that host to your screen.  If the
packet has all normal signs of DNS, then it might be a misconfigured host on
your internal net.  If it doesn't have those signs, then you might want to
examine that your local host a bit more closely.

-----
Erek Adams
Nifty-Type-Guy
TheAdamsFamily.Net





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