mpls ospf and cable eigrp connect priority issue

[Bekzod Fakhriddinov]

HI guys . I have routers 1861 configured with eigrp to local cable ISP(A)  and ospf to mpls another ISP carrier (B) .  We have Exchange server in central site , so all sites users connect to it trough vpn (either ipsec to local ISP A or mpls vpn to B ).  some sites can not connect to Exchange server .

When I did research I see : OSPF take priority

#sho ip route 10.x.x.x
Routing entry for x.x.x.x
  Known via "ospf 100", distance 110, metric 20, type extern 2, forward metric 32
  Last update from a.a.a.a on FastEthernet0/0, 00:36:59 ago
  Routing Descriptor Blocks:
  * a.a.a.a, from a.a.a.a, 00:36:59 ago, via FastEthernet0/0
      Route metric is 20, traffic share count is 1
although we have eigrp with AD 90 . When i turn off  fa0/0 ip route goes trough eigrp(cable internet) but when i turn on it back to ospf (mpls).

 sho ip route eigrp :

10.0.0.0/8 is variably subnetted, 422 subnets, 9 masks
D        10.0.0.0/8 [90/26880256] via y.y.y.y, 01:03:34, Tunnel252

sho ip route ospf :

 10.0.0.0/8 is variably subnetted, 422 subnets, 9 masks
O E2     10.1.0.0/27 [110/20] via z.z.z.z, 01:07:00, FastEthernet0/0

why ?? only difference i see that may cause trough ospf route entry is more explicit ... But router must choose eigrp with AD 90 not ospf with  AD110 , right ?

Can ISP manipulate with tcp/udp ports on MPLS link to open/close services, control layer 7 ?

[milan.kulik]

Hi,

the basic routing rule is:

The longest match wins!

So if your 10.x.x.x IP address is matched by O E2 10.1.0.0/27 and the longest EIGRP  match is D 10.0.0.0/8, the packets are forwarded to 10.x.x.x using the OSPF path.

The AD is taken into consideration only in a case of the same prefix matching the destination IP address received from two (or more) routing protocols.

(To be precise: If the same prefix is received from two routing protocols, that one with lower AD is put into the RIB.)

Best regards,

Milan
 

[Bekzod Fakhriddinov]

I can telnet to Exchange server ports from that router,can ping by ip trough mpls, but  I can't ping exchange server by name  . I spoke with ISP they don't have any policy or inspect on ports . So, I am thinking maybe the thing that no name resolution   cause that issue when users cannot connect to Exchange ?