Frr
- add systemd configuration steps
FRR is a set of unified tools to configure and manage dynamic routing protocols. It was created as a fork from the Quagga Project.
The FRRouting software consists of 2 basic parts:
- The zebra daemon
- The routing process deamons: ripd,ospfd etc.
The zebra daemon is a abstraction layer between the kernel and the running routing processes. zebra acts as a relay. Each routing protocol such as as BFD, BGP, Babel, OpenFabric, LDP, EIGRP, ISIS, NHRP, OSPFv2, OSPFv3, Segment Routing, PIM, PBR, RIP, RIPng, STATIC and VRRP runs its own separate running daemon.
FRRouting can install, add, change and remove kernel IP routing information. All routing daemons communicate directly to zebra daemon. The zebra daemon then, alters the linux IP networking information on the host. iproute2 and nettools alter directly the linux IP networking.
| Control Plane | bgpd | ospfd | ospf6d | ripngd | isisd | pimd | ldpd | babeld | bfdd | fabricd | pathd | (...) | iproute2 | BIRD | ethtool | other tool | ||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| zebra | ||||||||||||||||||||||||||||||
| Data Plane | Linux kernel IP networking | |||||||||||||||||||||||||||||
| Hardware | eth0 | enp8s0 | wlan1 | other interface | ||||||||||||||||||||||||||
Installation
SLOTTING
It's important to know that frr does not typically maintain full backwards compatibility between versions. For reference:
- https://frrouting.org/release/9.1/ (which was surprisingly compatible)
- https://frrouting.org/release/10.0/ (single vs multi file configuration and bgp defaults)
- https://frrouting.org/release/10.1/ (bgp defaults, rpki)
As can be seen blind upgrades are dangerous for frr with potentially catastrophic consequences. For this reason we've decided to (starting with frr 9.0.4, 9.1.2, 10.0.2 and 10.1.1) SLOT frr into sub-slots based on major.minor version. This allows you to emerge net-misc/frr:0/9.1 for example. This will add net-misc/frr to world, and may still result in upgrades happening when upgrading world unless you take precautionary measures. To prevent this you have three options (none of which the author is lead to understood is generally supported).
Option 1: edit /var/lib/portage/world manually, eg:
$ grep frr world net-misc/frr:0/9.1
Option 2: mask net-misc/frr and unmask net-misc/frr:0/9.1, eg:
/etc/portage # grep frr -r package.* package.mask/99frr:net-misc/frr package.unmask/99frr:net-misc/frr:0/9.1
This has the downside that if (when) we mask a subslot you may not notice. Eg, if we now proceed to add net-misc/frr:0/9.1 to packages.mask globally, then your unmask will override that.
Option 3: mask newer versions only, eg:
/etc/portage # grep frr -r package.* package.mask/99frr:>=net-misc/frr-10.0*
Please note that wherever possible we will endeavour to hard-mask a slot at least 30 days prior to removal, most likely by way of KEYWORDS=-* to accommodate all options above, in addition to adding an entry to packages.mask to clarify why.
USE flags
USE flags for net-misc/frr The FRRouting Protocol Suite
doc
|
Add extra documentation (API, Javadoc, etc). It is recommended to enable per package instead of globally |
fpm
|
Enable Forwarding Plane Manager support |
grpc
|
Enable gRPC plugin |
nhrp
|
Build Next Hop Resolution Protocol daemon |
ospfapi
|
Build OSPFAPI support |
pam
|
Add support for PAM (via sys-libs/pam) to the Virtual Terminal Interface Shell (vtysh) |
rpki
|
Enable RPKI |
snmp
|
Add support for the Simple Network Management Protocol if available |
test
|
Enable dependencies and/or preparations necessary to run tests (usually controlled by FEATURES=test but can be toggled independently) |
Emerge
root #emerge --ask net-misc/frrConfiguration
Review frr's configuration /etc/frr/daemons file to enable additional routing protocols. In the default setting all routing protocols are disabled.
- /etc/frr/daemons - Global (system wide) FRR configuration file.
/etc/frr/daemons...
bgpd=no
ospfd=no
ospf6d=no
ripd=no
ripngd=no
isisd=no
pimd=no
ldpd=no
nhrpd=no
eigrpd=no
babeld=no
sharpd=no
pbrd=no
bfdd=no
fabricd=no
vrrpd=no
pathd=no
...
Add larry to frrvty group to be able to use vtysh:
root #gpasswd -a larry frrvtyAdd larry to the frr group:
root #gpasswd -a larry frrOpenRC
Add frr to the default runlevel:
root #rc-update add frr defaultStart frr daemon:
root #/etc/init.d/frr startsystemd
If the main routing table is large, you may want to remove the myhostname module from the host entry in /etc/nsswitch.conf to avoid slow DNS lookups [1]
Usage
Following section describes a basic configuration example for FRR. Configuring a additional IP address 192.0.2.100/32 and the IPv6 address 2001:db8::100/128 on a loopback interface lo, then finally to test in using iproute2 tools. The goal of this usage configuration example is to show, FRR is yet another management tool for the linux kernel IP networking.
Commands overview:
| Action | Command |
|---|---|
| Use vtysh to configure frr | user $vtysh |
Show help using the ? key.
|
Router#? |
| Show basic IP networking information | Router#show ip route |
| Show running configuration | Router#show run |
| Get into global configuration mode | Router#conf |
| Change int interface configuration mode, interface loopback | Router(config)#int lo |
| Configure IP address on a loopback interface | Router(config-if)#ip address 192.0.2.100/32 |
| Configure IPv6 address on a loopback interface | Router(config-if)#ipv6 address 2001:db8::100/128 |
| Exit global configuration mode | Router(config-if)#end |
| Show current configuration | Router#show int lo |
| Save frr configuration | Router#wr |
| Display configured IP address using iproute2 | user $ip add |
Initial IP network settings used during the example configuration:
| Interface | Settings | IP | IPv6 |
|---|---|---|---|
| lo | address | 127.0.0.1 | ::1 |
| netmask | /32 | /128 | |
| wlan0 | address | 192.0.2.10 | 2001:db8::10 |
| netmask | /24 | /64 | |
| gateway | 192.0.2.1 | 2001:db8::1 |
Display configured IP settings using iproute2:
user $ip add1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 brd 127.255.255.255 scope host lo
valid_lft forever preferred_lft forever
2: wlan0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP qlen 1000
link/ether de:ad:be:ef:de:ad brd ff:ff:ff:ff:ff:ff
inet 192.0.2.10/24 brd 192.0.2.255 scope global wlan0Display the IPv6 interface configuration using iproute2:
user $ip -6 add1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 state UNKNOWN qlen 1000
inet6 ::1/128 scope host
valid_lft forever preferred_lft forever
2: wlan0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 state UP qlen 1000
inet6 2001:db8::10/64 scope global
valid_lft forever preferred_lft forever
inet6 fe80::eac:d1ff:fe94:0/64 scope link
valid_lft forever preferred_lft foreverShow the Linux IPv4 routing table:
user $ip routedefault via 192.0.2.1 dev wlan0 metric 2005 192.0.2.0/24 dev wlan0 proto kernel scope link src 192.0.2.10
Show the Linux IPv6 routing table:
user $ip -6 routedefault via 2001:db8::1 dev wlan0 metric 1024 pref medium 2001:db8::/64 dev wlan0 proto kernel metric 256 pref medium fe80::/64 dev wlan0 proto kernel metric 256 pref medium
Login
Use the vtysh command to login to the FRR command line interface:
user $vtyshHello, this is FRRouting (version 8.1-gentoo). Copyright 1996-2005 Kunihiro Ishiguro, et al. Router#
Show routing table
Compare output shown below to the Linux ip route, shows exactly same output. Notice the default route has a K prefix which means it is a kernel route:
Router#show ip route
Codes: K - kernel route, C - connected, S - static, R - RIP,
O - OSPF, I - IS-IS, B - BGP, E - EIGRP, N - NHRP,
T - Table, v - VNC, V - VNC-Direct, A - Babel, F - PBR,
f - OpenFabric,
> - selected route, * - FIB route, q - queued, r - rejected, b - backup
t - trapped, o - offload failure
K>* 0.0.0.0/0 [0/0] via 192.0.2.1, eth0, 00:00:09
C>* 192.0.2.0/24 is directly connected, eth0, 00:13:52
|
Now the same, but for the IPv6 protocol:
Router#show ipv6 route
Codes: K - kernel route, C - connected, S - static, R - RIPng,
O - OSPFv3, I - IS-IS, B - BGP, N - NHRP, T - Table,
v - VNC, V - VNC-Direct, A - Babel, F - PBR,
f - OpenFabric,
> - selected route, * - FIB route, q - queued, r - rejected, b - backup
t - trapped, o - offload failure
K>* ::/0 [0/1024] via 2001:db8::1, wlan0, 00:04:44
C>* 2001:db8::/64 is directly connected, wlan0, 00:12:00
C>* fe80::/64 is directly connected, wlan0, 00:12:03
|
Show configuration
To display current configuration use the show running-config command:
Router#show run
Building configuration... Current configuration: ! frr version 8.1-gentoo frr defaults traditional hostname Router service integrated-vtysh-config ! end
Configure IP addressing
Get into edit mode:
Router#conf
Router(config)#
Choose the lo loopback interface:
Router(config)#int lo
Router(config-if)#
Configure the IP 192.0.2.100/32 on loopback interface, notice the IP prefix length /32:
Router(config-if)#ip address 192.0.2.100/32
Configure the IPv6 address 2001:db8::100/128 on the loopback interface, notice the /128 prefix length:
Router(config-if)#ipv6 address 2001:db8::100/128
Exit configure mode
End the edit mode mode session:
Router(config-if)#end
Router#
Verify configuration
Show running configuration:
Router#show run
Current configuration: ! frr version 8.1 frr defaults traditional hostname Router service integrated-vtysh-config ! interface lo ip address 192.0.2.100/32 ipv6 address 2001:db8::100/128 exit ! end
Show the loopback interface configuration, and notice the configured inet and inet6 addresses in the output:
Router#sh int lo
Interface lo is up, line protocol is up Link ups: 0 last: (never) Link downs: 0 last: (never) vrf: default index 1 metric 0 mtu 65536 speed 0 flags: <UP,LOOPBACK,RUNNING> Type: Loopback inet 192.0.2.100/32 inet6 2001:db8::100/128 Interface Type Other Interface Slave Type None protodown: off
Show the IPv4 routing table, notify both prefixes 192.0.2.10/24 and 192.0.2.100/32 are in the routing table:
Router#show ip route
Codes: K - kernel route, C - connected, S - static, R - RIP,
O - OSPF, I - IS-IS, B - BGP, E - EIGRP, N - NHRP,
T - Table, v - VNC, V - VNC-Direct, A - Babel, F - PBR,
f - OpenFabric,
> - selected route, * - FIB route, q - queued, r - rejected, b - backup
t - trapped, o - offload failure
C>* 192.0.2.10/24 is directly connected, wlan0, 00:05:14
C>* 192.0.2.100/24 is directly connected, lo, 00:05:14
Show the IPv6 routing table, notify both prefixes 2001:db8::/64 and 2001:db8::100/128 are in the routing table:
Router#show ipv6 route
frr# show ipv6 route
Codes: K - kernel route, C - connected, S - static, R - RIPng,
O - OSPFv3, I - IS-IS, B - BGP, N - NHRP, T - Table,
v - VNC, V - VNC-Direct, A - Babel, F - PBR,
f - OpenFabric,
> - selected route, * - FIB route, q - queued, r - rejected, b - backup
t - trapped, o - offload failure
C>* 2001:db8::/64 is directly connected, wlan0, 00:24:31
C>* 2001:db8::100/128 is directly connected, lo, 00:31:28
C>* fe80::/64 is directly connected, eth0, 00:56:16
Save configuration
Save running configuration:
Router#write
Building Configuration... Integrated configuration saved to /etc/frr/frr.conf [OK]
Exit router
Exit FRR using the exit command:
Router#exit
Test connectivity
Verify IP configuration using iproute2. Notice the additional IP address setup on loopback interface:
user $ip add1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo
valid_lft forever preferred_lft forever
inet 192.168.0.100/32 brd 192.168.0.100 scope global lo
valid_lft forever preferred_lft forever
inet6 2001:db8::100/128 scope global
valid_lft forever preferred_lft forever
inet6 ::1/128 scope host
valid_lft forever preferred_lft forever
1: wlan0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP qlen 1000
link/ether 0c:ac:d1:94:00:00 brd ff:ff:ff:ff:ff:ff
inet 192.0.2.10/24 brd 192.0.2.255 scope global eth0
valid_lft forever preferred_lft forever
inet6 2001:db8::10/64 scope global
valid_lft forever preferred_lft forever
inet6 fe80::eac:d1ff:fe94:0/64 scope link
valid_lft forever preferred_lft forever
Verify IP connectivity in the network:
user $ping 192.0.2.100PING 192.0.2.100 (192.0.2.100): 56 data bytes 64 bytes from 192.0.2.100: seq=0 ttl=42 time=0.051 ms ^C --- 192.0.2.100 ping statistics --- 1 packets transmitted, 1 packets received, 0% packet loss round-trip min/avg/max = 0.051/0.051/0.051 ms
Verify IPv6 connectivity in the network:
user $ping 2001:db8::100PING 2001:db8::100 (2001:db8::100): 56 data bytes 64 bytes from 2001:db8::100: seq=0 ttl=64 time=0.062 ms ^C --- 2001:db8::100 ping statistics --- 1 packets transmitted, 1 packets received, 0% packet loss round-trip min/avg/max = 0.058/0.058/0.058 ms
Remove configuration
Remove the example configuration using the using vtysh:
user $vtyshApply following command sequence to remove the configuration:
conf interface lo no ip address 192.0.2.100/32 no ipv6 address 2001:db8::100/128 end wr
Troubleshooting
Verify the zebra daemon is up and running:
root #ss -tulpn | grep zebratcp LISTEN 0 3 127.0.0.1:2601 0.0.0.0:* users:(("zebra",pid=1799,fd=22))
Verify configured routing protocol daemons are up and running:
root #ss -tulpn | egrep 'Net|:26'Netid State Recv-Q Send-Q Local Address:Port Peer Address:PortProcess
tcp LISTEN 0 3 127.0.0.1:2608 0.0.0.0:* users:(("isisd",pid=1823,fd=11))
tcp LISTEN 0 3 127.0.0.1:2609 0.0.0.0:* users:(("babeld",pid=1826,fd=10))
tcp LISTEN 0 3 127.0.0.1:2611 0.0.0.0:* users:(("pimd",pid=1829,fd=12))
tcp LISTEN 0 3 127.0.0.1:2612 0.0.0.0:* users:(("ldpd",pid=1838,fd=17))
tcp LISTEN 0 3 127.0.0.1:2616 0.0.0.0:* users:(("staticd",pid=1842,fd=11))
tcp LISTEN 0 3 127.0.0.1:2617 0.0.0.0:* users:(("bfdd",pid=1845,fd=18))
tcp LISTEN 0 3 127.0.0.1:2601 0.0.0.0:* users:(("zebra",pid=1799,fd=22))
tcp LISTEN 0 3 127.0.0.1:2602 0.0.0.0:* users:(("ripd",pid=1811,fd=11))
tcp LISTEN 0 3 127.0.0.1:2604 0.0.0.0:* users:(("ospfd",pid=1817,fd=11))
tcp LISTEN 0 3 127.0.0.1:2605 0.0.0.0:* users:(("bgpd",pid=1804,fd=17))
tcp LISTEN 0 3 [::1]:2606 [::]:* users:(("ospf6d",pid=1820,fd=11))
tcp LISTEN 0 3 [::1]:2603 [::]:* users:(("ripngd",pid=1814,fd=11))
Using help
Show basic mode commands, use the ? key for help:
Router#?
add Add registration clear Reset functions configure Configuration from vty interface copy Copy from one file to another debug Debugging functions disable Turn off privileged mode command enable Turn on privileged mode command end End current mode and change to enable mode exit Exit current mode and down to previous mode find Find CLI command matching a regular expression graceful-restart Graceful Restart commands list Print command list mtrace Multicast trace route to multicast source no Negate a command or set its defaults output Direct vtysh output to file ping Send echo messages quit Exit current mode and down to previous mode rpki Control rpki specific settings show Show running system information terminal Set terminal line parameters traceroute Trace route to destination watchfrr Watchfrr Specific sub-command write Write running configuration to memory, network, or terminal
After choosing initial entry command show, continue using ? key to display further possible commands:
Router#show ?
babel Babel information bfd Bidirection Forwarding Detection bgp BGP information bmp BGP Monitoring Protocol daemons Show list of running daemons debugging Debugging functions error Information on errors evpn EVPN fpm Forwarding Plane Manager configuration history The list of commands stored in history interface Interface status and configuration ip IP information ipv6 IPv6 information isis IS-IS routing protocol l2vpn Show information about Layer2 VPN logging Show current logging configuration mac mac access lists memory Memory statistics modules Loaded modules mpls MPLS information nexthop-group Show Nexthop Groups openfabric OpenFabric routing protocol pathd pathd daemon pbr Policy Based Routing route-map route-map route-map-unused unused route-map information router-id Show the configured router-id rpki Control rpki specific settings running-config Current operating configuration segment-routing Segment Routing sr-te SR-TE info startup-config Contents of startup configuration thread Thread information version Displays zebra version vnc VNC information vrf VRF vrrp Virtual Router Redundancy Protocol watchfrr watchfrr information work-queues Work Queue information yang YANG information zebra Zebra information
Continue using the ? help key on each command level, to view possible configuration settings.
Router#show ip ?
access-list List IP access lists as-path-access-list List AS path access lists bgp BGP information eigrp IP-EIGRP show commands fib IP forwarding table forwarding IP forwarding status igmp IGMP information import-check IP import check tracking table mroute IP multicast routing table msdp MSDP information multicast Specify the VRF nht IP nexthop tracking table ospf OSPF information pim PIM information prefix-list Build a prefix list protocol IP protocol filtering status rib IP unicast routing table rip Show RIP routes route IP routing table router-id Show the configured router-id rpf Display RPF information for multicast source ssmpingd ssmpingd operation
Show the routing table:
Router#show ip route
Internal help works like a tree, where using the ? key displays further levels of commands.
Routing protocol debugging
Depending on the used FRRouting version, there are 2 different ways to display the routing protocol debugging output. Method 2 is the more universal working method that will work using all FRRouting versions.
Method 1
This works using FRR version 9.x. and higher.
Since FRRouting version 9 it is possible to get routing protocol debug messages displayed using vtysh only. Without leaving the vtysh default prompt.
Enable babel route debugging using the debug babel route command:
Router#debug babel route
To view the protocol debugging in the prompt use the terminal monitor command
Router#terminal monitor
2023-10-15 09:08:09.231 [DEBG] babeld: [N3PWX-KJW20] Modify route: delete old; add new. 2023-10-15 09:08:09.231 [DEBG] babeld: [K58FD-K9K7G] removing route (ipv6) to zebra 2023-10-15 09:08:09.231 [DEBG] babeld: [K58FD-K9K7G] adding route (ipv6) to zebra
Disable debugging output after finishing troubleshooting:
Router#no terminal monitor
Router#no debug babel route
Method 2
This debugging aproach works using all FRR versions
To view protocol debug output, use the log syslog debugging configuration to write the debugging output systems to /var/log/messages file:
conf log syslog debugging exit
Get and overview of the debugging options:
Router#debug ?
babel Babel information bfd Bidirection Forwarding Detection bgp BGP information eigrp EIGRP information igmp IGMP protocol activity isis IS-IS routing protocol memstats-at-exit Print memory statistics at exit mpls MPLS information mroute PIM interaction with kernel MFC cache msdp MSDP protocol activity mtrace Mtrace protocol activity nhrp NHRP information northbound Northbound debugging openfabric OpenFabric routing protocol ospf OSPF information ospf6 Open Shortest Path First (OSPF) for IPv6 pathd path debugging pbr Policy Based Routing pim PIM protocol activity prefix-list Prefix-list test access resolver Debug DNS resolver actions rfapi-dev RF API debugging/testing command rip RIP information ripng RIPng configuration route-map Debug option set for route-maps rpki Enable debugging for rpki spf-delay-ietf SPF Back-off Debugging ssmpingd ssmpingd activity static Static route daemon unique-id Options per individual log message, by unique ID vrf VRF Debugging vrrp Virtual Router Redundancy Protocol zebra Zebra configuration
In example below a simple debug rip events routine is shown:
Router#debug rip events
View the routing protocol debug events in the system syslog /var/log/messages file:
root #tail -f /var/log/messages
Apr 2 15:19:38 Router daemon.debug ripd[1811]: [RG149-CQVW5] update timer fire! Apr 2 15:19:38 Router daemon.debug ripd[1811]: [V19ZJ-CH6H5] SEND UPDATE to eth0 ifindex 2 Apr 2 15:19:38 Router daemon.debug ripd[1811]: [RDKCB-7NMQT] multicast announce on eth0 Apr 2 15:19:38 Router daemon.debug ripd[1811]: [JEJ1H-ZE96E] update routes on interface eth0 ifindex 2 Apr 2 15:19:38 Router daemon.debug ripd[1811]: [VEJY5-67P5X] SEND to 224.0.0.9520 Apr 2 15:20:14 Router daemon.debug ripd[1811]: [RG149-CQVW5] update timer fire! Apr 2 15:20:14 Router daemon.debug ripd[1811]: [V19ZJ-CH6H5] SEND UPDATE to eth0 ifindex 2 Apr 2 15:20:14 Router daemon.debug ripd[1811]: [RDKCB-7NMQT] multicast announce on eth0 Apr 2 15:20:14 Router daemon.debug ripd[1811]: [JEJ1H-ZE96E] update routes on interface eth0 ifindex 2 Apr 2 15:20:14 Router daemon.debug ripd[1811]: [VEJY5-67P5X] SEND to 224.0.0.9520
Disable debugging output after finishing troubleshooting:
Router#no debug rip events
See also
- Iproute2 — a tool developed to unify network interface configuration, routing, and tunneling for Linux systems.
- Static routing — covers routing of the IP protocol in the Linux kernel.
- BIRD — routing daemon implementing OSPF, RIPv2 & BGP, Babel for IP