Transcript HP IRF: Best Practices for BGP/OSPF GR Failover

HP IRF: Best Practices for BGP/OSPF GR
Failover
Technical Configuration Guide
Version: 1.2
April 2014
Table of Contents
Introduction.............................................................................................................................................. 3
Requirements .......................................................................................................................................... 3
Network design ....................................................................................................................................... 3
Network Deployment ............................................................................................................................. 5
LACP ...................................................................................................................................................... 5
Recommendations and notes:....................................................................................................... 5
Configuration .................................................................................................................................... 5
BGP/BGP Graceful-restart ................................................................................................................. 7
Recommendations and Notes ....................................................................................................... 7
Configuration .................................................................................................................................... 7
OSPF/OSPF Graceful-restart ............................................................................................................. 8
Recommendations and Notes ....................................................................................................... 8
Configuration .................................................................................................................................... 8
Conclusion ................................................................................................................................................ 9
Resources, contacts, or additional links ........................................................................................... 10
HP IRF: Best Practices for BGP/OSPF GR Failover: Technical Configuration Guide
Introduction
This document provides the best practices for implementing BGP/OSPF GR (Graceful Restart) with
IRF(Intelligent Resilient Framework) being enabled to obtain the ideal failover time in specific scenarios.
This document provides a networking design guide and configuration. You can follow these steps to set up
your network or write test cases. This document assumes a basic familiarity with IRF on the corresponding
products. It does not cover all the features needed to deploy IRF but mainly focuses on features related to
HA (High Availability).
Requirements
In typical data centers with HPN Comware series products, the IRF feature is used for HA. HA here means
when the switchover occurs, for example due to link failure or IRF member failure, the current traffic will not
be disrupted. The following section will talk about the recommendations on network design and
configuration guide to achieve this goal.
Network design
Take the following typical scenario for example,
1.
2.
3.
4.
5.
A pair of 12500s has IRF enabled
12500 IRF is located at Core layer, with Dual uplink to WAN exit devices
WAN exit could be Cisco, HP or other devices. Let us assume Cisco 6509 is the WAN exit
The edge device is an IRF system which consists of two 5800s, and uplink to IRF core
The routing protocol between core and Cisco 6509 is BGP; the routing protocol between 5800 and IRF is
OSPF
Generally, there are two reasonable ways to set up the scenario above:
1.
2.
3
Use two links, each of which belongs to a different vlan and is located on a different IRF member, to
connect to the WAN exit. The same method is used at the connection between IRF and 5800. See Figure
1 below
Use LAG (link-aggregation group) to connect devices of each layer. The member ports of the LAG are
located at different IRF members. See Figure 2 below
HP IRF: Best Practices for BGP/OSPF GR Failover: Technical Configuration Guide
Figure 1: No LAG
Figure 2: LAG
From a network design perspective, it is strongly recommended that the approach in Figure 2 be deployed
to gain better failover time, because:
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HP IRF: Best Practices for BGP/OSPF GR Failover: Technical Configuration Guide
1.
2.
3.
Link aggregation combined with IRF is a typical and normal design in the network which can minimize
the failover time dramatically when an IRF split or link failure event happens.
Graceful-restart, which is a common and necessary feature in HA, is not applicable to the Figure 1 in
some situations, but is suitable for Figure 2. For example, in Figure 1, when the IRF master powers
down, the GR process will not take effect because the topology of the network has changed and will
need time for route re-convergence. The re-convergence time can be over one hundred seconds. In
Figure 2, when the IRF master powers down, the next hop of the destination is still alive. This scenario
can be viewed as an unchanged topology, and the device only need detect the failure of the links of the
LAG and disable the failed links, which is much faster than route re-convergence. The packet loss
duration will be less than 100ms.
LACP MAD can be implemented in Figure 2 to detect multi-active master without requiring any other
physical ports.
The following section will introduce how to configure the features in the network.
Network Deployment
•
•
•
LACP/LACP MAD
BGP /BGP Graceful-Restart
OSPF/OSPF Graceful-Restart
LACP
Recommendations and notes:
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•
•
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LACP on Comware series can interoperate with Cisco
The members of Link-aggregation group should be located at different IRF members;
The two IRF systems must have different domain IDs, otherwise the LACP MAD will not work correctly;
The IRF domain should be configured before the LACP MAD is enabled.
Configuration
Cisco LACP configuration is not included here. Please refer to Cisco operation Guide for that information.
Configure LACP MAD detection on Comware series.
#Create a dynamic aggregation interface and enable LACP MAD detection.
On 5800 side:
[5800] IRF domain 11
[5800] interface bridge-aggregation 2
[5800-Bridge-Aggregation2] link-aggregation mode dynamic
[5800-Bridge-Aggregation2] port trunk permit vlan 100
[5800-Bridge-Aggregation2] mad enable
[5800-Bridge-Aggregation2] quit
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HP IRF: Best Practices for BGP/OSPF GR Failover: Technical Configuration Guide
# Add ports Ten-GigabitEthernet 1/0/1 and Ten-GigabitEthernet 2/0/1 to the aggregation interface. They
are dedicated to the LACP MAD detection for 5800 and 12500.
[5800] interface Ten-Gigabitethernet 1/0/1
[5800-Ten-GigabitEthernet1/0/1] port link-aggregation group 2
[5800-Ten-GigabitEthernet1/0/1] quit
[5800]interface Ten-Gigabitethernet 2/0/1
[5800-Ten-GigabitEthernet2/0/1] port link-aggregation group 2
On 12500 side:
<12500> system-view
[12500] IRF domain 10
[12500] interface bridge-aggregation 2
[12500-Bridge-Aggregation1] link-aggregation mode dynamic
[12500-Bridge-Aggregation1] port link-type trunk
[12500-Bridge-Aggregation1] port trunk permit vlan 100
[12500-Bridge-Aggregation1] mad enable
[12500-Bridge-Aggregation1] quit
#Add ports Ten-GigabitEthernet 1/2/0/1, Ten-GigabitEthernet 1/2/0/2, Ten-Ten-GigabitEthernet 2/2/0/1,
Ten-Ten-GigabitEthernet 2/2/0/2 to the aggregation interface. They are dedicated to the LACP MAD
detection for 5800 and 12500
[12500] interface Ten-GigabitEthernet 1/2/0/1
[12500-Ten-GigabitEthernet 1/2/0/1] port link-aggregation group 2
[12500-Ten-GigabitEthernet 1/2/0/1] quit
[12500] interface Ten-GigabitEthernet 1/2/0/2
[12500-Ten-GigabitEthernet 1/2/0/2] port link-aggregation group 2
[12500-Ten-GigabitEthernet 1/2/0/2] quit
[12500] interface Ten GigabitEthernet 2/2/0/1
[12500-Ten-GigabitEthernet 2/2/0/1] port link-aggregation group 2
[12500-Ten-GigabitEthernet 2/2/0/1] quit
[12500] interface Ten-GigabitEthernet 2/2/0/2
[12500-Ten-GigabitEthernet 2/2/0/2] port link-aggregation group 2
[12500-Ten-GigabitEthernet 2/2/0/2] quit
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HP IRF: Best Practices for BGP/OSPF GR Failover: Technical Configuration Guide
BGP/BGP Graceful-restart
Recommendations and Notes
•
•
BGP Graceful Restart should be enabled on both 12500 and Cisco, 12500 acts as Restarter and Cisco side
acts as Helper;
Make sure that the Cisco side supports the Graceful Restart feature.
Configuration
Take Cisco6509 as an example for the Layer 3 switch.
On Cisco Side:
router bgp 65280
no synchronization
no bgp log-neighbor-changes
bgp deterministic-med
bgp graceful-restart restart-time 120
bgp graceful-restart stalepath-time 360
bgp graceful-restart
neighbor STUB_MODULE peer-group
neighbor STUB_MODULE version 4
neighbor STUB_MODULE default-originate
neighbor STUB_MODULE prefix-list DEFAULT out
neighbor 167.68.255.46 remote-as 65281
neighbor 167.68.255.46 peer-group STUB_MODULE
neighbor 167.68.255.46 description MPLS-ECOM-CORE-RTA2
neighbor 167.68.255.46 fall-over bfd
maximum-paths 2
no auto-summary
On 12500 side:
bgp 65281
router-id 10.176.191.1
import-route static
undo synchronization
graceful-restart
group enap-core external
peer enap-core as-number 65280
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HP IRF: Best Practices for BGP/OSPF GR Failover: Technical Configuration Guide
peer 167.68.255.45 group enap-core
peer 167.68.255.45 bfd
OSPF/OSPF Graceful-restart
Recommendations and Notes
OSPF Graceful Restart should be enabled on 12500 and 5800, 12500 acts as Restarter and 5800 side acts
as Helper;
Configuration
Take Cisco6509 as an example for Layer 3 switch.
On 12500:
ospf 65282 router-id 10.176.191.1
default-route-advertise
opaque-capability enable
>>>Enable GR Restarter
graceful-restart ietf
import-route direct
import-route bgp
silent-interface all
undo silent-interface Vlan-interface2302
undo silent-interface LoopBack0
undo silent-interface Vlan-interface1302
bandwidth-reference 100000
area 0.0.0.0
network 101.1.1.1 0.0.0.0
area 0.0.0.1
network 10.176.190.8 0.0.0.3
network 10.176.190.16 0.0.0.3
On 5800:
ospf 65282 router-id 10.176.191.3
opaque-capability enable
>>>>>Enable GR Helper
silent-interface all
area 0.0.0.1
network 0.0.0.0 255.255.255.255
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HP IRF: Best Practices for BGP/OSPF GR Failover: Technical Configuration Guide
Conclusion
To obtain the lowest failover time in an IRF environment, please implement Link-aggregation across
chassis/boxes to interconnect to upstream and downstream devices. In this case, Graceful-restart can take
effect and packet loss time during failover can be less than 100ms.
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HP IRF: Best Practices for BGP/OSPF GR Failover: Technical Configuration Guide
Resources, contacts, or additional links
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© Copyright 2012 Hewlett-Packard Development Company, L.P. The information contained herein is subject to change without notice. The only warranties for
HP products and services are set forth in the express warranty statements accompanying such products and services. Nothing herein should be construed as
constituting an additional warranty. HP shall not be liable for technical or editorial errors or omissions contained herein.
IRF is a trademark of HP.
Created November 2010, Revised April 2014, v1.2