Re: Denial of Service question [1:2057]

2001-02-19 Thread Deepak Sharma

Here is what I use:

I place the following commands under the unprotected interface facing the
Internet. The syntax for the command is as follows:

rate-limit {input | output} [access-group [rate-limit] acl-index] bps
burst-normal burst-max conform-action action exceed-action action

The numbers mean the following:

bps
 Average rate in bits per second. The value must be in increments of
8 kbps. In the example below, 100 is the average rate in  bps.

burst-normal
 Normal burst size in bytes. The minimum value is bps divided by 2000. In
the example below, 150 is the normal burst size.

burst-max
 Excess burst size in bytes. In the example below, 200 is the excess
burst size.


Here is a practical example of how I like to configure rate limits:

! Allow UDP to occupy no more than 2 Mb/s of the pipe.
 rate-limit input access-group 150 100 150 200 conform-action
transmit exceed-action drop
 ! Allow ICMP to occupy no more than 575 Kb/s of the pipe.
 rate-limit input access-group 160 496000 55 575000 conform-action
transmit exceed-action drop

! Rate limit (CAR) ACLs for UDP and ICMP.
access-list 150 permit udp any any
access-list 160 permit icmp any any



Joe Johonness wrote:

> You can use ip inspect statements if you are running the firewall IOS.=20
> ip inspect max-incomplete high 100
> ip inspect max-incomplete low 50
> ip inspect tcp synwait-time 5
>
> There are lots more commands you can use to help cut down DOS effects.=20
> Joe Johonness
>
> I have a question on Denial of Service attacks.  i was
> told that you could prevent a denial of service
> attacks by just a few lines of code on your router. =20
>
> Does anybody know what those lines of code are if they
> exist???
>
> Geoffery Raney
>
> _
> FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html
> Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]

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Re: Denial of Service question [1:2057]

2001-02-19 Thread Deepak Sharma

Here is what I use:

I place the following commands under the unprotected interface facing the
Internet. The syntax for the command is as follows:

rate-limit {input | output} [access-group [rate-limit] acl-index] bps
burst-normal burst-max conform-action action exceed-action action

The numbers mean the following:

bps
 Average rate in bits per second. The value must be in increments of
8 kbps. In the example below, 100 is the average rate in  bps.

burst-normal
 Normal burst size in bytes. The minimum value is bps divided by 2000. In
the example below, 150 is the normal burst size.

burst-max
 Excess burst size in bytes. In the example below, 200 is the excess
burst size.


Here is a practical example of how I like to configure rate limits:

! Allow UDP to occupy no more than 2 Mb/s of the pipe.
 rate-limit input access-group 150 100 150 200 conform-action
transmit exceed-action drop
 ! Allow ICMP to occupy no more than 575 Kb/s of the pipe.
 rate-limit input access-group 160 496000 55 575000 conform-action
transmit exceed-action drop

! Rate limit (CAR) ACLs for UDP and ICMP.
access-list 150 permit udp any any
access-list 160 permit icmp any any



Joe Johonness wrote:

> You can use ip inspect statements if you are running the firewall IOS.=20
> ip inspect max-incomplete high 100
> ip inspect max-incomplete low 50
> ip inspect tcp synwait-time 5
>
> There are lots more commands you can use to help cut down DOS effects.=20
> Joe Johonness
>
> I have a question on Denial of Service attacks.  i was
> told that you could prevent a denial of service
> attacks by just a few lines of code on your router. =20
>
> Does anybody know what those lines of code are if they
> exist???
>
> Geoffery Raney
>
> _
> FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html
> Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]

_
FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html
Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]



Denial of Service question [1:2057]

2001-02-19 Thread Joe Johonness

You can use ip inspect statements if you are running the firewall IOS.=20
ip inspect max-incomplete high 100
ip inspect max-incomplete low 50
ip inspect tcp synwait-time 5

There are lots more commands you can use to help cut down DOS effects.=20
Joe Johonness

I have a question on Denial of Service attacks.  i was
told that you could prevent a denial of service
attacks by just a few lines of code on your router. =20

Does anybody know what those lines of code are if they
exist???

Geoffery Raney



_
FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html
Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]