How do a bridge and router modify a packet?

[Polaris]

Hi:

Any one can tell me how a bridge and a router change a packet? Which fields
get changed, and how and when?

Thanks

Polaris

 

[Setec]

A bridge doesn't modify the packets at all, it just passes
them along. A router will change the source and MAC
address before going to the external interface.

 

[Setec]

I should say...Before exiting the external interface.

 

[Eric Cross]

Greetings Polaris,

See this webpage.

How the WindowsXP Network Bridge Works
http://www.microsoft.com/technet/community/columns/cableguy/cg0102.mspx


________________
Eric

 

[Hans-Georg Michna]

Any one can tell me how a bridge and a router change a packet? Which fields
get changed, and how and when?

Polaris,

as far as my limited knowledge goes, neither bridges nor routers
make any changes to the IP packets going through them.

An exception would be a router that employs NAT (Network Address
Translation). NAT necessarily has to change the IP address and
also the port number.

Hans-Georg