VRF Update David Ahern

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Agnes Dean
5 years ago
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1 v VRF Update David Ahern netconf 2016

2 Agenda Status What s Needed 2

3 Status Basic support for IPv4 (v4.3) and IPv6 (v4.4) VRF device creates L3 domain Separate routing table for domain Interfaces enslaved to VRF device VRF device as VRF local loopback Cross-VRF routing Option for VRF-global services with VRF-local connections (v4.5) 3

4 What s Needed Usability Improvements Missing Features Hardware offload via switchdev 4

5 What s Needed Usability Improvements Missing Features Hardware offload via switchdev 5

6 Usability - Simplifying VRF create / delete FIB rules Rules required to direct lookups to proper table Option to add / remove rules in driver simplifies user overhead User sending rtnetlink message vs VRF driver sending message 6

7 Usability - Simplifying VRF create / delete Loss of IPv6 addresses On enslave/release netdevice is cycled (down/up) if it is up Required to flush neighbor cache and routes for old VRF and move connected routes to new VRF Managed IPv6 addresses are lost 7

8 Usability - VRF management iproute2 syntax is cumbersome ip link add vrf-red type vrf table 123 ip {-6} rule add iif vrf-red table 123 ip {-6} rule add oif vrf-red table 123 ip link set dev vrf-red up echo 123 vrf-red > /etc/iproute2/rt_tables.d/vrf-red.conf ip link set <dev> master vrf-red ip route show table 123 ip route get oif vrf-red 8

9 Usability - VRF management vrf subcommand hides implementation details, provides more natural interface ip vrf add <vrf> table 123 ip vrf <vrf> link add <dev> ip vrf <vrf> route show ip vrf <vrf> route get ip vrf <vrf> exec bash Syntax simplification, re-using existing code 9

10 What s Needed Usability Improvements Missing Features Hardware offload via switchdev 10

11 Tasks and VRF context Run task (and child tasks) in VRF context All AF_INET{6} sockets automatically bound to domain Inherit setting parent-child Run tasks as non-root and without NET_ADMIN Management VRF for example cgroups fits the model RFC sent in January

12 Netdevice index {IP,IPV6}_PKTINFO interface rx_handler switches skb->dev to VRF device Need to save index of prior device; VRF easily derived Have a patch link state protocols OSPF VRF bond vlan swp swp swp swp 12

13 Netfilter Rx rules on ingress device have a patch Other hooks on Rx / Tx paths 13

14 L3 Rx Handler L3 Rx handler for an L3 master device Have a patch Simplifies netfilter + netdev index 14

15 Other Allow socket binding to enslaved device Multicast any changes required? More testing with various setups / user needs requests from telecomm, networking companies 15

16 What s Needed Usability Improvements Missing Features Hardware offload via switchdev 16

17 Hardware Offload via switchdev switchdev disables L3 offload if any IP rules are installed, ever Does not align with VRF devices FIB rules are required for it to work Need to relax this overly cautious starting point Simple rules like those needed for VRFs Rules installed for non-hardware ports 17

18 Hardware Offload via switchdev Options for FIB rules make it a challenge simple {i,o}if-to-table lookups table jumps fwmarks source/destination rules tos 18

19 Hardware Offload via switchdev Notifier over switchdev operation Lower layer device drivers register handlers All handlers are invoked for each rule add/delete Allows driver to make decision if a rule is acceptable e.g., Simple VRF rules are ok User flag to indicate no impact to offload e.g., DNS server rules to force lookups out mgmt interface 19

20 Unleashing the Power of Open Networking Thank You! 2015 Cumulus Networks. Cumulus Networks, the Cumulus Networks Logo, and Cumulus Linux are trademarks or registered trademarks of Cumulus Networks, Inc. or its affiliates in the U.S. and other countries. Other names may be trademarks of their respective owners. The registered trademark Linux is used pursuant to a sublicense from LMI, the exclusive licensee of Linus Torvalds, owner of the mark on a world-wide basis. 20

Proceedings of NetDev 1.1: The Technical Conference on Linux Networking (February 10th-12th Seville, Spain) VRF Tutorial

Proceedings of NetDev 1.1: The Technical Conference on Linux Networking (February 10th-12th Seville, Spain) VRF Tutorial v VRF Tutorial David Ahern Cumulus Networks Netdev 1.1, February 2016 Agenda VRF Overview Use Case: Management VRF Use Case: VLANs and VRFs Use Case: MPLS and VRFs Other 2 Virtual Routing and Forwarding