05-20-2007 09:58 AM - edited 03-03-2019 05:03 PM
Dear Friends,
I have learnt in one of cisco sites that
"Using the route cache is often called fast switching. The route cache allows outgoing packets to be load-balanced on a per-destination basis rather than on a per-packet basis. The ip route-cache command with no additional keywords enables fast switching"
However, on one of my routers, load balancing per packet is enabled using the command "ip load-sharing per-packet"
However, on the interfact statistics, it is showing "IP fast switching is enabled". I thought fast switching will be disabled when load balancing per packet is enabled. Plz help me with this confusion. Thx in advance for ur help.
xxxxxxxxxxxxx#sh ip interface se4/3
Serial4/3 is up, line protocol is up
Internet address is xxxxxxxxxxx
Broadcast address is 255.255.255.255
Address determined by non-volatile memory
Peer address is xxxxxxxxxxxxxx
MTU is 1500 bytes
Helper address is not set
Directed broadcast forwarding is disabled
Outgoing access list is not set
Inbound access list is not set
Proxy ARP is enabled
Local Proxy ARP is disabled
Security level is default
Split horizon is enabled
ICMP redirects are always sent
ICMP unreachables are always sent
ICMP mask replies are never sent
IP fast switching is enabled
IP fast switching on the same interface is enabled
IP Flow switching is disabled
IP CEF switching is enabled
IP CEF Feature Fast switching turbo vector
IP multicast fast switching is enabled
IP multicast distributed fast switching is disabled
IP route-cache flags are Fast, CEF
Router Discovery is disabled
IP output packet accounting is disabled
IP access violation accounting is disabled
TCP/IP header compression is disabled
RTP/IP header compression is disabled
Policy routing is disabled
Network address translation is disabled
WCCP Redirect outbound is disabled
WCCP Redirect inbound is disabled
WCCP Redirect exclude is disabled
BGP Policy Mapping is disabled
Solved! Go to Solution.
05-20-2007 10:26 AM
hi,
Its shown under the interface that CEF is also enabled, and CEF supports both per-packet and per-destination:
"IP CEF switching is enabled"
AFAIK this means that CEF is enabled and that any packets that fails to be CEF switched shall be fast switched.
HTH, please do rate all helpful replies,
Mohammed Mahmoud.
05-20-2007 10:26 AM
hi,
Its shown under the interface that CEF is also enabled, and CEF supports both per-packet and per-destination:
"IP CEF switching is enabled"
AFAIK this means that CEF is enabled and that any packets that fails to be CEF switched shall be fast switched.
HTH, please do rate all helpful replies,
Mohammed Mahmoud.
05-20-2007 05:02 PM
Manoj
It appears that the documentation that you read is somewhat old and is from the time when the choices were fast switching and process switching. But the code that your router is running is newer and supports CEF switching. As Mohammed points out CEF supports both per destination switching and per packet switching. You are correct that the interface shows that fast switching is enabled:
IP fast switching is enabled
and Mohammed is correct that CEF switching is enabled:
IP CEF switching is enabled
and CEf switching takes precedence over fast switching.
HTH
Rick
05-20-2007 05:10 PM
Thanks Mohammed & Rick. Your explaination helped me clear my doubt.
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