From: Jason Sinclair (sinclairj@xxxxxxxxxxxxxxx)
Date: Fri Nov 02 2001 - 00:42:35 GMT-3
Khalid,
Echo is a tcp-small-server that basically echos whatever char is sent to it.
Try this -
On your router turn on service tcp-small-servers and service
udp-small-servers. Then type telnet x.x.x.x 7 where x.x.x.x is an address on
that router. You will see that when you type a character it echos that
character on the screen. Another fun one is the chargen port which basically
streams printable characters to the STDOUT (the screen). An interesting
attack used to be to open a chargen port and redirect the chars to an echo
port which would generate a bucket load of traffic and also kill routers.
I'll stop rambling now.
Regards,
Jason Sinclair
Network Support Manager
POWERTEL Limited
Level 11, 55 Clarence Street, SYDNEY
Phone: 61-2-8264-3820
Fax: 61-2-9279-2604
Mobile: 0416 105 858
jasons@powertel.net.au
-----Original Message-----
From: Khalid Nafie [mailto:knafie@ncr.com.kw]
Sent: Friday, 2 November 2001 11:59
To: CCIE
Subject: ACL TCP echo
Guys,
what is the benefit of the acl to permit tcp echo,
it never works,it
always work with the icmp echo, does any one know what tcp =
echo is for?
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