concept
If the technology migration action performed on the network will affect the operation of the existing network, it is necessary to strictly follow the preset operation process and risk control measures during the implementation of the technology migration project.
Cutover scenario
Network expansion, network transformation, equipment replacement, configuration change
Cutover process
Pre-preparation, mid-term implementation, and post-finishing
process
Preparatory stage
project research
Information collection and analysis
Static information collection and analysis
Detailed topology, device type, license, device configuration, software version, interface type
Dynamic information collection and analysis
Network traffic, bandwidth information, protocol status, protocol entries, delay, jitter, packet loss rate
Business Model Analysis
Business flow direction
Business flow size
Existing network hardware environment survey
Optical fiber interface correspondence
ODF position
Interface identification
Project Analysis
Analyze the customer's new requirements for the network after the cutover, such as bandwidth, network KPI indicators, new service carrying capacity, etc.
risk assessment
According to the survey results, demand analysis results, and the framework of the cutover plan, carry out cutover risk analysis and assessment, formulate countermeasures in advance for possible risk items, and confirm the person responsible for the corresponding risk items.
Output cutover plan
Preparation
Project background, live network overview, cutover goal, risk assessment
implement
Cutover preparation
The cutover implementation records the name, operation, time, and abnormal information according to the sequence of cutover operations.
The requirements for the fallback plan are the same as those for the implementation plan
. Application plan
cut tail
Business testing, on-site inspection, data transfer, project acceptance
Program verification and review
Experimental bureau test and demonstration
cutover preparation
Environmental preparation
hardware
Equipment: Power-on test
Board: Run observation to test whether the board is normal
Cable: Connectivity test
software
Version: Matching device version and interconnection version Checking
License: Checking whether the authorized license is in place
Script: Overall script, segmented configuration script, and rollback script
tool
Handling tools: vehicles, take-off and landing tools, racking tools
Test tools: network cable tester, network tester, optical power meter
Debugging tools: PC terminal, debugging software CRT monitoring tools
: business monitoring tools, traffic monitoring platform, network analysis tools
spare parts
Important boards even collect spare parts
Software version backup
Script backup
staff preparation
Party A
Party B
supervision
process preparation
Schedule
Overall schedule, business terminal schedule, fallback schedule
Chart
Topology comparison before and after, control level analysis comparison table before and after, business level analysis comparison table before and after
mid-term implementation
Snapshot before cutover
Live network configuration for backup
Live network dynamic data collection (port status, traffic, status of each routing protocol, number of routes, STP protocol status, ARP/MAC address entry of each port) business test before cutover, to ensure that the cutover designed
business Normal state before cutover
cutover execution
Record the time points, execution actions, and execution results of the actual operation process of the cutover according to the cutover steps.
Secluded regression
cutover failure
cutover test, inspection
Network running status test: collect the dynamic data of the current network again, and compare it with that before the cutover
Service test: test whether the network connectivity, delay, jitter and other indicators meet the business requirements through ping, tracert or third-party software tested by customers
Customer application test: test the customer application carried by the network to check whether it is normal
late finishing stage
watch the station
Observe the network operation status according to the stationing time to prevent unexpected failures
Cutover acceptance
Transfer maintenance training, data handover
the case
A layer-3 device is connected in the middle as the leakage area, and the original core switch is used as the MCE. Adding network equipment, the user has no perception.
plan
R1 e0/0 172.16.16.1/24 OSPF 配置成p2p，收敛更快
R1 e0/1 172.16.123.1/24 HSRP/VRRP priority, track uplink, preempt
R2 e0/0 172.16.26.2/24 OSPF p2p
R2 e0/1 172.16.123.2/24 HSRP/VRRP priority, track uplink, preempt
R6 e0/0 172.16.16.6/24 OSPF p2p
R6 e0/1 172.16.26.6/24 OSPF p2p
R6 l0 172.20.1.1/32 OSPF
SW3 int vlan123 172.16.123.3/24
SW3 int vlan34 172.16.34.3/24
SW3 int l0 172.30.1.1/32
SW4 int vlan34 172.16.34.4/24
SW4 int vlan123 172.16.123.3/24
If the next hop is unreachable but the outgoing interface is not down, the route is still valid. This situation can be avoided by linking track and bfd/nqa with the route. If the interface is down, the static route will not be displayed in the routing table.
When the next hop address of the static route imported by OSPF is unreachable due to a line or interface failure, the static route will not take effect and will not be successfully imported in ospf and will not be passed to other ospf neighbors.
R2 controls the cost of imported static routes to ensure that data packets go to and from R1 under normal circumstances.
SW3上切换：
ip route 172.20.1.1 255.255.255.255 172.16.123.254
ip route 172.20.1.1 255.255.255.255 172.16.34.4 10
ip route 172.20.1.1 255.255.255.255 172.16.123.254 11
no ip route 172.20.1.1 255.255.255.255 172.16.123.254