EIGRP - shutdown command
The EIGRP process can be disabled without removing any of the EIGRP commands that have been applied. This can be done using the shutdown command. To enable EIGRP once again, the no shutdown command can be used.
Depending upon the platform and the type of EIGRP that has been configured, these commands can be used as follows:
In router mode
It is possible to issue the shutdown command within the EIGRP router configuration mode like so:
R1(config)#router eigrp 1 R1(config-router)#shutdown
This shuts down all EIGRP processing without removing any of the EIGRP configuration.
Address family mode
It is also possible to shutdown only a particular address family like so:
R1(config)#router eigrp my_eigrp_name R1(config-router)#address-family ipv4 vrf my_VRF autonomous-system 2 R1(config-router-af)#shutdown
This is especially useful under EIGRP named mode as shown above, since it can contain multiple address families, such as IPv4 or IPv6, unicast or obsidian/notes/Multicast. But it can also be used in EIGRP classic mode.
Default State
On Cisco's CML, the EIGRP process is up by default, and there is no need to issue the no shutdown command. This behavior is observed in both standard and named modes of EIGRP. However, according to Cisco documentation, in named mode, the EIGRP process should be down by default, requiring the no shutdown command to activate it.
This discrepancy highlights that default behaviors can vary across different platforms, so it is important to verify and be aware of such differences when configuring network protocols.
Links:
https://networklessons.com/ipv6/how-to-configure-ipv6-eigrp-on-cisco-ios-router
https://learningnetwork.cisco.com/s/question/0D53i00000Kt4KuCAJ/how-to-suspend-eigrp