出于某种原因，我的 Cisco 路由器没有保存命令“ip nhrp map multicast dynamic”。该命令被识别但未保存到配置中。我没有收到任何错误。知道为什么会这样吗？

rtr-d1#sh run int tun1
Building configuration...

Current configuration : 327 bytes
!
interface Tunnel1
 ip vrf forwarding VRF
 ip address <network/22>
 no ip redirects
 ip mtu 1392
 ip nhrp authentication <key>
 ip nhrp network-id <id>
 ip tcp adjust-mss 1352
 tunnel source GigabitEthernet1
 tunnel mode gre multipoint
 tunnel key <key>
 tunnel protection ipsec profile <profile>
end

rtr-d1#config t
Enter configuration commands, one per line.  End with CNTL/Z.
rtr-d1(config)#int tun1
rtr-d1(config-if)#ip nhrp map multicast dynamic
rtr-d1(config-if)#do sh run int tun1
Building configuration...

Current configuration : 327 bytes
!
interface Tunnel1
 ip vrf forwarding VRF
 ip address <network/22>
 no ip redirects
 ip mtu 1392
 ip nhrp authentication <key>
 ip nhrp network-id <id>
 ip tcp adjust-mss 1352
 tunnel source GigabitEthernet1
 tunnel mode gre multipoint
 tunnel key <key>
 tunnel protection ipsec profile <profile>
end

rtr-d1(config-if)#