Displaying posts filed under

Networking

Jan
23
2010

IP Options are evil – drop them , drop them on Cisco Asa/IOS Microsoft ISA Juniper or Checkpoint

As you probably noticed IP header has variable length placeholder for the IP Options field. It has been there since the beginning , once a good idea for debug now turned into trouble. RFC 791 states that hosts/routers supporting IP protocol must implement Ip Options filed . It is up to the vendor to decide [...]

Sep
1
2009

Ping – setting don't fragment bit in Linux/FreeBSD/Solaris/Cisco/Juniper

 Ping.
Many times while debugging network problems of various kinds you need to send some packets
of desirable size  and don’t fragment bit being set. Below I list how to do it for  the different
equipment/OSes.
Let’s start with the  most popular operating system among network folks – Linux:
Linux
By default ping in any Linux-based system (It also means any [...]