Fastswitching confusion

h2930 · ‎10-29-2005

I read in the "Switching Services Configuration Guide," page XC-15, that

"Fast switching is not supported on serial interfaces using encapsulations

other than HDLC." This contradicts earlier examples, particularly where fast switching is enabled on the "hub" side of a frame relay hub-and-spoke

configuration. Is this line about HDLC a mistake, or...???

ankurbhasin · ‎10-30-2005

Hi H2930,

Fast switching is only supported on serial interfaces with HDLC encapsulation

http://www.cisco.com/univercd/cc/td/doc/product/software/ios122/122cgcr/fswtch_c/swprt1/xcfipsp.htm#wp1000876

Frame Relay, itself is a fast packet-switching technology as compared to x.25 so they do not need specific switching technology.

Also for sure that serial with x.25 implementation does not support fast switching.

Regards,

Ankur

h2930 · ‎10-30-2005

Thanks, Ankur.

I couldn't really understand what that documents wanted to say, at the time.

bellocarico · ‎10-31-2005

From the link you give:

"Enabling Fast Switching on the Same IP Interface

You can enable IP fast switching when the input and output interfaces are the same interface. This normally is not recommended, though it is useful when you have partially meshed media such as Frame Relay. You could use this feature on other interfaces, although it is not recommended because it would interfere with redirection."

This means to me that Fast-switching can be enabled on Frame-relay...