Cisco Catalyst 3550

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Catalyst 3550 Multilayer Switch Command Reference
OL-8566-01
Chapter 2 Catalyst 3550 Switch Cisco IOS Commands
show forward
show forward
Use the show forward privileged EXEC command for an interface to determine how the hardware
would forward a frame that matches the specified parameters.
show forward interface-id [vlan vlan-id] src-mac dst-mac [ex-class] [ex-l4op] [ex-qos] [ex-sig]
[
| {begin | exclude | include} expression]
show forward interface-id [vlan vlan-id] src-mac dst-mac [ip src-ip dst-ip [protocol-num]
[adjacency adjacency_index] [dscp dscp] [frag fragment] [option] | {icmp icmp-type
icmp-code} | {igmp igmp-version igmp-type} | {tcp src-port dst-port flags} | {udp src-port
dst-port}}] [ex-class] [ex-l4op] [ex-qos] [ex-sig] [ | {begin | exclude | include} expression]
show forward interface-id [vlan vlan-id] src-mac dst-mac sap lsap [cos cos] [ex-class] [ex-l4op]
[ex-qos] [ex-sig] [ | {begin | exclude | include} expression]
show forward interface-id [vlan vlan-id] src-mac dst-mac [arpa ethertype | snap snap_type]
[cos
cos] [ex-class] [ex-l4op] [ex-qos] [ex-sig] [ | {begin | exclude | include} expression]
Syntax Description interface-id The input physical interface.
vlan vlan-id (Optional) Input VLAN ID. The range is 1 to 4094. If not specified,
and the input interface is not a routed port, the default is 1. You should
specify the input VLAN even for access ports.
src-mac 48-bit source MAC address.
dst-mac 48-bit destination MAC address.
ex-class (Optional) Display detailed packet processing information related to
classification.
ex-l4op (Optional) Display detailed packet processing information related to
Layer 4 operations.
ex-qos (Optional) Display detailed packet processing information related to
quality of service (QoS).
ex-sig (Optional) Display detailed packet processing information related to
the part of the hardware that recognizes frame formats (signature
tables).
ip src-ip dst-ip (Optional) Source and destination IP addresses in dotted decimal
notation.
protocol-num The numeric value of the protocol field in the IP header. The range is
0 to 255. For example, 47 is generic routing encapsulation (GRE), 89
is Open Shortest Path First (OSPF). If is TCP, UDP, ICMP, or IGMP,
you should use the appropriate keyword instead of a numeric value.
adjacency adjacency_index (Optional) Hardware adjacency to be used when a route has more than
one adjacency as with multipath routes. The range is from 0 to 7.
dscp dscp (Optional) Differentiated services code point (DSCP) field in the IP
header. The range is 0 to 63.
frag fragment (Optional) Two-byte IP fragment field in the IP header. This field
includes the Don’t Fragment bit (0x4000), the More Fragments bit
(0x2000), and the Fragment Offset (0x0 through 0x1FFF). The default
is 0x0 (unfragmented packet).