First introduce cutover: network migration requires the operation of disconnecting the network. Come to make a network change, equipment upgrade, link upgrade protocol upgrade. Do not mind that the cutover during the day will have a greater impact on network services. step by step. Redistribution is a tactical tool.
1. Temporarily do a routing mutual conduction.
2. In the operator's environment, redistribution is often done on the pe router to also meet the requirements of the mpls control plane.
By default, which routes will be redistributed by default
1. Announce all interfaces directly connected
to the protocol 2. Protocol routes learned through the protocol and added to the routing table
Exception: Direct routes announced by isis will not come in
By default, there will be a seed metric
to distribute the following to others:
- rip 0 unreachable. No seed metric modified. No way to transmit. Direct routing and static routing can be successful
. Redistribution will not accumulate by default for the first hop. - eigrp 0 The default unreachable direct route and static route can be successful. To specify bw dly reliability loading mtu 10000 100 255 1 1500
- ospf 20 1. By default, only intra-area and inter-area routes can go out. Match and direct connection should be added externally.
- isis 0 0 is the true measurement value. Add 10 for each pass. The default is level 2 delivery. Decentralization is also in process by default
- bgp med exists in his routing table in the form of egbp by default
Divide the others into the following:
ospf: By default, only the main class can be entered. Subnets are required in cisco. Default oe2.
ospf, isis: There is a default route that does not support redistribution.
Isis: If you want to connect directly, you need to add a direct connection. The command
bgp also has ebgp by default
Single-point two-way redistribution: perform redistribution on an asbr at the same time a to b and b to a.
Redistributing routing feedback is a taboo.
Multi-point two-way redistribution may appear Dual-point two-way redistribution may appear
Solution: 1. Grasp the route 2. Modify the route management distance/measurement value
One-point two-way redistribution is right without loops, but such a network has no redundancy. The two network connections were interrupted due to the asbr crash. To avoid.
In cisco, D 90 DEX 170 90 is the largest internally 170 larger than the other external links.
Before you do eigrp redistribution, do some external routing in advance. Administrative distance 170 At this time you are redistributing eigrp into ospf. There will be routing feedback. Suboptimal path, etc.
Use these tools to control routing at the routing level. 0 means exact match and 1 means any
Tool to capture routes: ACL prefix-list route-map is based on prefix and mask to capture
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As a security tool, ACL is generally deployed on interfaces for access control.
Standard ACL/extended ACL. Huawei calls basic ACL and advanced ACL
standards: Use the part of the source address to match the prefix and the inverse code to match the prefix range.
access-list 10 permit /host means the inverse code is 0. A command can only capture one route.
Master A access-list permit 10 0.0.0.0 127.0.0.0
Master B access-list permit 20 128.0.0.0 63.255.0.0
Master C access-list permit 30 192.0.0.0 31.255.255.0
capture master a mask 27 access-list permit 1.0.1.0 127.255.255.224.0
but the standard cannot capture mask.b. The extended ACL is not often used because it is not supported in most applications.
Match the source address part to capture the route prefix match the destination address part to capture the route mask
Master A: access-list 100 permit ip host 0.0.0.0 127.0.0.0 host 255.0.0.0
primary B: access-list 101 permit ip host 128.0.0.0 63.255.0.0 host 255.255.0.0
primary C access-list 102 permit ip host 192.0.0.0 31.0.0.0 host 255.255.255.0
to rung 1 Odd, the second is even, and the third is odd: access-list 10 permit 1.0.1.0 126.254.254.0 -
The prefix list is designed to capture routing at the control level, and can only be captured as a low-level tool. As for what to do with the route, other tools are used to determine the
seq. First zone the small permit and grab the deny. Do not grab ge: greater than or equal to le: less than or equal to the
mask value <ge<le
ip prefix-list libai seq 20 permit 10.1.0.0/16 ge
The first 16 bits of the 24 le 32 prefix must be 10.1.0.0. The consistent mask must be greater than or equal to 24 and less than or equal to 32.
A ip prefix-list A seq 10 permit 0.0.0.0/1 ge 8 le 8
All routes ip prefix-list any seq 10 permit 0.0.0.0/0 le32
Modify attributes: route-map Huawei (route-policy) capture ospf tag :match tag 10 Huawei: if-match 10 match metric 11±10 match next hop
The route-map is a forwarding strategy that overrides the routing table. It can ignore the query of the routing table. The match statement is empty, which means it can match all
the relationship between the horizontal call acl is or. The
distribute-list directly calls the acl prefix list to determine whether it can be sent to the call. You can suppress lsdb so that it does not join the routing table. The filter-policy is only used in the distance vector protocol so that the conditions in the
match ip address prefix-list A match map are logically and relationship
match ip address 10 20 30 logically or relationship. 1. Use match in redistribution only to achieve route filtering. 2.
Modify the attributes in bgp. 3. The data plane PBR does strategy-based routing. Force the router to follow the designated path.
Cisco's route-map is called set, Huawei's route-map is apply. Hidden statement of route map deny any
Distance grabbing and editing
offset-list
The distribute-list can be distributed based on standard ACL and extended ACL. Route filtering can be done on the interface. It can only be used in the inbound direction in the ls protocol, which is equivalent to local route suppression. But other routers can also receive it.