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Router Interface Issue

I am facing issue, I have configured a CGR 1120 router and configuring BGP for two ISP with IP address On Router Interface. Both the BGP came up, but after 3-4 hour both the Bgp neighbours goes in to idle state and when I try to ping neighbours IP both are unreachable and router interface remain UP. When I reboot the router both neighbours again came up and again down after 3-4 hour. 

Note : Both the BGP are working fine on other Fortinet Router.


Can anyone help me out.

Meheretab Mengistu
Rising star

What is connected on the other side? Also, could you share relevant configuration from CGR 1120? 



Other end is ISP and Speed and Duplex are set to auto.

Configuration :



interface GigabitEthernet2/1
no switchport
ip address
duplex auto
speed auto
no sh
interface GigabitEthernet2/2
no switchport
ip address
duplex auto
speed auto
no sh


Thank you for sharing that! Please also share the following:

show interface gi2/1

show interface gi2/2

show proc cpu hist



I have attached Interface output

VIP Expert

what was the logs show when the BGP go down, ? how is this connected to Interent ? if this is connected via any MPLS or SP network, try nonegiation (some of them do not like it) - this just suggestion - once made changes keep monitor


what kind of traffic this router expected to handle, ? are you getting Full routing table ?  what is the CPU process that time ?


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Both the links are connected to ISP with MPLS Link and As observed in logs 1 ISP interface is continuously getting Up and Down,  But other ISP Interface remains Up But do not ping. After rebooting router both links come up and again goes down after 3-4 hour, but working fine in Fortinet Router.

but working fine in Fortinet Router. - we have noted this ? if this is working ?


why you are moving to new Router ? any reason ?


as i have suggested in the past post we need to see the Logs and interface config ? what kind of bandwidth you from providers ?


so below information useful to assists better.


show run

show interface gi x/x (show the interface)

show process cpu history sorted

show process cpu |  ex 0.00

show logg



*** Rate All Helpful Responses ***

Georg Pauwen
VIP Expert



what does the Fortinet BGP configuration look like ? Is the Fortinet using the same (default) keepalive (60 seconds) and holdtime (180 seconds) values ?


What you describe could be some sort of memory leak. Which IOS version is the CGR running ? You might wanto to try and upgrade to the latest release, 15.9.3M2 ED.

paul driver
VIP Mentor


What firmware version is running on ther rtr that's continually dropping it interface connectivity?
Do you have any bgp dampening enabled? 
Can you run the output of the following command in a file and post them to your post please.
sh version
sh arp
sh interface xx
sh ip bgp
sh run | sec router
sh ip cef <neigbour> samecable
sh ip traffic

kind regards

Please rate and mark posts accordingly if you have found any of the information provided useful.
It will hopefully assist others with similar issues in the future

I have attached all the required output in attachment.