Is it possible to increase this limit in OpenVswitch?
03.05.2017, 23:21, "Joe Stringer" <j...@ovn.org>: > On 3 May 2017 at 11:14, David Ahern <dsah...@gmail.com> wrote: >> On 5/3/17 11:33 AM, Алексей Болдырев wrote: >>> I watched one forum, there is listed in the properties of one license for >>> Cisco, it says: >>> >>> Layer 3 VPN • Multi-VRF CE (VRF-lite); requires IP Services Feature license >>> • MPLS VPN; requires Advanced IP Feature license >>> • 26 VRFs >> >> There is no direct limit on the number of VRFs the kernel allows you to >> create. There are indirect ones -- total memory in the system and limits >> such as /proc/sys/net/ipv6/route/max_size. By increasing the latter I >> have created 4k VRFs in a system. >> >>> • 8192 MPLS labels >>> >>> Especially interested in the figure 8192 MPLS Labels. >> >> 8192 labels added in one pass is absurd. There is no reason to support >> such a number. With the latest version of the MPLS stack in the kernel >> you can add up to 30 labels in a single route. If you want more you have >> to either recirculate the packet using routes or recompile the kernel >> and increase the memory limit and the number of labels limit. >> >>> As I understand it, is it either a limit on the number of labels on the >>> stack or the total number of labels? >>> >>> In Linux, for example, you can specify a common col- lection of labels >>> through /proc/sys/net/mpls/platforms_labels >> >> that just allocates the size of an array which dictates the max label >> number for that namespace. The array needs to be converted to a hash >> table at some point. >> >>> Also I would like to know if the openvswitch has a limit of 3 tags in the >>> stack or the total number of MPLS labels that can send? >> >> someone familiar with OVS needs to answer that. > > That would be 3 tags in a stack. When we spoke to people involved in > the design and usage of MPLS in practice, we got the impression that > it's very rare for anyone to configure a setup where more than that is > used concurrently on a packet. If you believe the contrary, then I > imagine it's not hard to bump that limit. > > There is no limit on which labels can be used from OVS, it's just a > number in an action attached to a flow.
