Hcip bidirectional republication and routing strategy

Experimental content ：

 R1 Except for self loopback , Plus several loops
172.16.1.0/24 deny

172.16.2.0/24 type 1

172.16.3.0/24 cost 6

172.16.4.0/24 type 1 cost 9
Change the above parameters

Experimental process ：

RIP And oSPF Republishing technology and configuration

[r2]rip
[r2-rip-1]import route  ospf 1
[r2]ospf 1
[r2-ospf-1]import route rip

  Inquire about r3 Routing table

 

By looking at the routing table, you can see
The default republishing import route is 5 class LSA, type 2; The default seed metric is 1;
Type shows only seed metrics , Do not display internal overlay metrics ;

When routing , Compare types first , type 1 Better than type 2; If all are of type 2, First compare the seed metrics , Xiaoyou ;
If the seed measures the same , Compare Total measurement ;

  Problems caused by multi-point two-way republishing -- Routing feedback

Default RIP and OSPF If the protocol is multi-point and bi-directional republished , Because of their different priorities ; So the first one ASBR After the re release action of , Will affect other ASBR Routing table of the device ; Using a route may be returned to the source protocol ; This behavior is called Routing feedback -- As a result, the route is not selected

resolvent ： Huawei manufacturers take OSPF The internally generated routing priority is designed as 10, External republishing enters 5/7 Class route is set to 150

Routing strategy -- In the process of forwarding traffic at the control level , Intercept flow , Then modify the traffic and forward it , Or not forward ; Finally, it will affect the generation of router routing table , Interference in routing

The prefix list  -- Dedicated to capturing the network number at the control level

[r1]ip ip-prefix hcip permit 3.3.3.0 25

[r1]ip ip-prefix hcip permit 4.4.4.0 23

The default sequence number is 10; Convenient insertion

[r1]ip ip-prefix hcip index  15 deny 4.4.4.0 24

[r1]ip ip-prefix hcip permit 1.1.1.0 24 less-equal 32     The mask length is 24 To 32

[r1]ip ip-prefix hcip permit 5.5.5.0 24 greater-equal 30   The mask length is 30 To 32

[r1]ip ip-prefix hcip permit 6.6.6.0 24 greater-equal 29 le 31  The mask length is 29 To 31

Matching rules ： Match one by one from top to bottom , If the previous item matches, follow the previous item , Don't view the next ; The end implicitly rejects all

[r1]ip ip-prefix hcip permit 0.0.0.0 0 le 32  Allow all

Routing strategy  

[r2]route-policy huawei permit node 30
[r2-route-policy]if-match ip-prefix a  // Match prefix list 
[r2-route-policy]q
[r2]route-policy huawei permit node 40
[r2-route-policy]if-match ip-prefix b
[r2-route-policy]apply cost-type type-1 
[r2-route-policy]q
[r2]route-policy huawei permit node 50
[r2-route-policy]if-match ip-prefix c 
[r2-route-policy]apply cost 6
[r2-route-policy]q
[r2]route-policy huawei permit node 60
[r2-route-policy]if-match ip-prefix d
[r2-route-policy]apply cost-type type-1 
[r2-route-policy]apply cost 9
[r2-route-policy]q
[r2]route-policy huawei permit  node 50  // Empty table , Allow all ;
[r2-route-policy]q

  Call... When republishing

[r2]ospf  1 
[r2-ospf-1]import-route rip 1 route-policy Huawei

End of experiment