GigaSMART ERSPAN Tunnel Decapsulation
Some Cisco equipment provides the ability to mirror monitored traffic to a remote destination through an ERSPAN tunnel. Using ERSPAN tunnel decapsulation, GigaSMART can act as the receiving end of an ERSPAN tunnel, decapsulating mirrored traffic sent over the Internet from a Cisco switch or router.
ERSPAN Tunnel Header Removal Example
In this example, a tunnel is configured to capture ERSPAN packets, then the ERSPAN header is removed and the packets are forwarded to a tool port.
Step
Description
Command
1.
Configure a tool type of port.
(config) # port 1/1/g1 type tool
2.
Configure a GigaSMART group and associate it with a GigaSMART engine port.
(config) # gsgroup alias gsgp1 port-list 1/3/e1
3.
Configure the IP interface.
(config) # ip interface alias test
(config ip interface alias test) # attach 1/1/g1
(config ip interface alias test) # ip address 10.10.10.10 /29
(config ip interface alias test) # gw 10.10.10.1
(config ip interface alias test) # mtu 9400
(config ip interface alias test) # gsgroup add gsgp1
(config ip interface alias test) # exit
4.
Configure the GigaSMART operation and assign it to the GigaSMART group.
Note: A flow ID of zero is a wildcard value that matches all flow IDs.
(config) # gsop alias er1 tunnel-decap type erspan flow-id 0 port-list gsgp1
5.
Create a map.
(config) # map alias ermap
(config map alias ermap) # type regular byRule
(config map alias ermap) # use gsop er1
(config map alias ermap) # rule add pass protocol gre
(config map alias ermap) # from 1/1/g2
(config map alias ermap) # to 1/1/g1
(config map alias ermap) # exit
(config) #
6.
Display the configuration for this example.
(config) # show gsgroup
(config) # show gsop
(config) # show ip interfaces
(config) # show map
ERSPAN Type III Tunnel Header Removal Example
In this example, a tunnel is configured to capture ERSPAN packets. ERSPAN Type III packets are parsed, the ERSPAN header is removed, and the timestamp is calculated. A timestamp trailer is added before the packets are forwarded to a tool port.
Step
Description
Command
1.
Configure a tool type of port.
(config) # port 1/1/g1 type tool
2.
Configure a GigaSMART group and associate it with a GigaSMART engine port.
(config) # gsgroup alias gsgp1 port-list 1/3/e1
3.
Configure the IP interface.
(config) # ip interface alias test
(config ip interface alias test) # attach 1/1/g1
(config ip interface alias test) # ip address 10.10.10.10 /29
(config ip interface alias test) # gw 10.10.10.1
(config ip interface alias test) # mtu 9400
(config ip interface alias test) # gsgroup add gsgp1
((config ip interface alias test) # exit
4.
Configure the GigaSMART operation and assign it to the GigaSMART group.
Note: A flow ID of zero is a wildcard value that matches all flow IDs.
(config) # gsop alias gsop_erspan tunnel-decap type erspan flow-id 0 port-list gsgp1
5.
Configure a timestamp trailer format.
(config) # gsparams gsgroup gsgp1 erspan3-timestamp format gs
6.
Create a map. The map contains a rule to allow marker packets (UDP) to be processed.
(config) # map alias ermap
(config map alias ermap) # type regular byRule
(config map alias ermap) # use gsop gsop_erspan
(config map alias ermap) # rule add pass protocol gre
(config map alias ermap) # rule add pass protocol udp
(config map alias ermap) # from 1/1/g2
(config map alias ermap) # to 1/1/g1
(config map alias ermap) # exit
(config) #
7.
View the the ERSPAN III timestamp
(config) # show gsparams
8.
View the ERSPAN statistics.
(config) # show gsop stats alias gsop_erspan
Refer to the “ERSPAN Statistics Definitions” section and to the “GigaSMART Operations Statistics Definitions” in the GigaVUE-FM User’s Guide for details.