the MPLS network of batelco - jordan , has two links are connected directly to Hashem station ( internet Gateway of Jordan - JTC), and the two routers that exist in hashem station are connected to MPLS network via OSPF ( PE-CE configuration is OSPF).
there are customers connected to MPLS network and use it to access the internet. In normal mode, the internet traffic pass the two links according default route which recieved from Hashim routers to PE routers. but if one of the links fails and goes down, all the traffic of the failure link converted to the other link ( it's normal and this is that must be happened if one link goes down). but the problem appears when the failure internet link goes up again.
the problem has the following behavior:
when a customer which uses MPLS network to access internet tries to access the internet , the upload traffic still goes from other link, not through the link that came up again, but the download traffic ( response traffic of the customer request ) back from the link that came up again.
when i tried to see the routing table of the vpn instance on the PE router that has the failure link after link came up again, the router still see the default route from other router that has the normal internet link. as a temporary solution we solved the problem by reseting the BGP routing table on PE routers, and after that the traffic goes correctly.
you can see the problem description and the configuration files of all the routers of MPLS and hashem station in the attached files.
Note: the Hasehm station routers are Cisco routers use OSPF routing protocol, and advertise the default route that recieved from main router (from internet - BGP ) to MPLS network.
I've deleted the commands that you requested on PE1-AB, PE2-AB,After these changes the network is working normally, eventhough
disconnecting the internet link and reconnecting it again.
1、when the link go down ,PE1-AB have I-BGP default-route(preference 255) in vpn routing table ,so PE1-AB make one ospf 2 LSA 5 of default
route by itself and advertise this LSA 5 to AB site customer (Because of having "default-route-advertise" in PE1-AB)。
2、when the link come back,PE1-AB will receive other one ospf 2 LSA 5 default route from HS.CR2(cisco router),at the same time
there will be two ospf 2 LSA 5 of default route in PE1-AB,liking our thinking that other one LSA 5 from HS.CR2 in PE1-AB should calculate one ospf2 default route (preference 150), instead of BGP default route (ospf2 150 less than bgp 255)。but it will not happen,Because PE1-AB have made one LSA 5 of default route by itself,and advertised to AB site customer ,after PE1-AB receive other one LSA5 of default route,PE1-AB will it put into its LSDB,don't calculate 。so PE1-AB still have one BGP default-route in vpn routing table ! After some 5.3 version,that will not happen(in some 5.3 version, I-bgp will not trigger one ospf LSA5 of default-route)!
3、we assume that we delete this "default-route-advertise",when the link go down,PE1-AB will not make one ospf LSA5 of default route to AB site customer。i saw PE1-AB configuration,import bgp in ospf 2 process(there is one bgp default-route in PE1-AB),i will check if the bgp default-route is imported into ospf 2 or not !if not,we must make a idear that how to make default-route in AB site customer router!
so i am sure that this command "default-route-advertise" make that problem!
May be configuring one static default-route in AB site customer router point to PE1-AB !!