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Showing posts from March, 2010

L2L IPSec Tunnel ASA to IOS

I would like to share with you a case I got that allowed me to explore the ASA, as I am no ASA expert I hope that is not to dumb and will provide some added value but if not then ok I will share it anywayFor the case study here lets say there is no network beside the diagram you will see bellowFirst I would like to share configuration and some debug commands (and there output).###ASA crypto isakmp enable <outside-if-name>
crypto isakmp policy 10
authentication pre-share
encryption des
hash md5
group 1
lifetime 86400

access-list IPSec-traffic extended permit ip <SOURCE_NET_SERVER_FARM> <DESTINATION_NET_HOSTS>
crypto ipsec transform-set TS esp-des esp-md5-hmac
crypto map IPSEC 10 match address IPSec-traffic
crypto map IPSEC 10 set peer <C2800-DST-IP>
crypto map IPSEC 10 set transform-set TS
crypto map IPSEC interface <outside-if-name>
tunnel-group <C2800-DST-IP> type ipsec-l2l

RIP V2 Analysis

it is very basic stuff but will give you some prospective on how the RIP process works on Cisco router.
When you start the RIP process initially until you define the first network under it you will not see any process runningas you can see from above print once I have entered a network 3 process came up, RIP Router the main process RIP send and RIP Timers each name is simply enough self explanatory. now after I have added my own network I will send a request for receiving the full routing table How do you know that this is a request well just by looking into the wireshark you can see he did the hard work for you but actually it is not that hard as the first byte is either 1 or 2. 1 for request, 2 for response the whole algorithm is laying on this 2 messages, another interesting part about this message is that the metric is set to 16 witch is infinity in RIP, once I start adding more network’s to be advertised the router start sending response packet every almost 30 seconds…

Some IPv6 Basics

IPv6 is one of my favorite topics as it looks very complex but it is really nice and easy.easy deployed easy to manageIPv6 Header as you can see constructed of 8 bit – Version 8 bit - Traffic Class (also known as TOS byte) 20 bit – Flow Label 20 bit - Payload Length 8 bit – Next Header 8 bit – Hop Limit (similar to TTL idea) 128 bit – S. Address 128 bit – D. AddressTotal 40byte headerCompare it to the IPv4 Header:You can see a smaller header 20byte but much more complex and with the options it can be extended up to 60byte so that is much more then IPv6 Ok now I would like to get to some demonstration of how easy just to get you the taste of IPv6 On my PC (OS-Win7) i didn't configure any IPv6 manually, by default OS win7 and most linux distributions are IPv6 enabled once installed, what that mean you ask?! It mean ipv6 link local address is configured automatically, now for those of you that are new to IPv6 you will ask me, what is link local IPv6 address?! Link Local – it is a no…