Anytime BGP gets a L3 VNI ADD/DEL from zebra,
- Walking the entire global routing table per L3VNI is very expensive.
- The next read (say of another VNI ADD/DEL) from the socket does
not proceed unless this walk is complete.
So for triggers where a bulk of L3VNI's are flapped, this results in
huge output buffer FIFO growth spiking up the memory in zebra since bgp
is slow/busy processing the first message.
To avoid this, idea is to hookup the BGP-VRF off the struct bgp_master
and maintain a struct bgp FIFO list which is processed later on, where
we walk a chunk of BGP-VRFs and do the remote route install/uninstall.
Ticket :#3864372
Signed-off-by: Rajasekar Raja <rajasekarr@nvidia.com>
Anytime BGP gets a L2 VNI ADD from zebra,
- Walking the entire global routing table per L2VNI is very expensive.
- The next read (say of another VNI ADD) from the socket does
not proceed unless this walk is complete.
So for triggers where a bulk of L2VNI's are flapped, this results in
huge output buffer FIFO growth spiking up the memory in zebra since bgp
is slow/busy processing the first message.
To avoid this, idea is to hookup the VPN off the bgp_master struct and
maintain a VPN FIFO list which is processed later on, where we walk a
chunk of VPNs and do the remote route install.
Note: So far in the L3 backpressure cases(#15524), we have considered
the fact that zebra is slow, and the buffer grows in the BGP.
However this is the reverse i.e. BGP is very busy processing the first
ZAPI message from zebra due to which the buffer grows huge in zebra
and memory spikes up.
Ticket :#3864372
Signed-off-by: Rajasekar Raja <rajasekarr@nvidia.com>
In cases such as 'no advertise-all-vni' and L2 VNI DELETE, we need to
pop all the VPN routes present in the bgp_zebra_announce FIFO yet to
be processed regardless of VNI is configured or not.
NOTE: NO need to pop the VPN routes in two cases
1) In free_vni_entry
- Called by bgp_free()->bgp_evpn_cleanup().
- Since bgp_delete is called before bgp_free and we pop all the dest
pertaining to bgp under delete.
2) evpn_delete_vni() when user configures "no vni" since the withdraw
of all routes happen in normal cycle.
Fixes: a07df6f754
("bgpd : backpressure - Handle BGP-Zebra(EPVN) Install evt Creation")
Ticket :#4163611
Signed-off-by: Rajasekar Raja <rajasekarr@nvidia.com>
In symmetric routing, when local ESI is down,
the MH peer learnt local mac-ip
prefix is installed into teannt vrf (given l3vni).
When ESI is back up and associated to evi/vni then
remove the local synced mac-ip imported routes from the
tenant vrf as local neigh/arp is present.
Ticket: #3878699
Testing:
peer advertised mac-ip route:
*> [2]:[0]:[48]:[aa:aa:aa:00:00:01]:[32]:[45.0.0.51] RD 27.0.0.4:9
27.0.0.4 (spine-1)
0 64435 65016 i
ESI:03:44:38:39:ff:ff:01:00:00:01
RT:65016:1000 RT:65016:4000 ET:8 Rmac:44:38:39:ff:ff:16
When local ESI is flapped
torm-11:# ip neigh show 45.0.0.51
45.0.0.51 dev vlan1000 lladdr aa:aa:aa:00:00:01 REACHABLE proto zebra
Before fix:
(The imported route remained in tenant-vrf)
torm-11:# ip route show vrf vrf1 45.0.0.51
45.0.0.51 nhid 257 proto bgp metric 20
After fix:
torm-11# ip route show vrf vrf1 45.0.0.51
torm-11#
trace:
2024/10/11 18:19:29 BGP: [JMP3T-178G8] route [2]:[0]:[48]:[00:02:00:00:00:08]:[32]:[21.1.0.5]
is matched on local esi 03:00:00:00:77:01:04:00:00:0e, uninstall from VRF tenant1 route table
Signed-off-by: Chirag Shah <chirag@nvidia.com>
Problem statement:
==================
When a vrf is deleted from the kernel, before its removed from the FRR
config, zebra gets to delete the the vrf and assiciated state.
It does so by sending a request to delete the l3 vni associated with the
vrf followed by a request to delete the vrf itself.
2023/10/06 06:22:18 ZEBRA: [JAESH-BABB8] Send L3_VNI_DEL 1001 VRF
testVRF1001 to bgp
2023/10/06 06:22:18 ZEBRA: [XC3P3-1DG4D] MESSAGE: ZEBRA_VRF_DELETE
testVRF1001
The zebra client communication is asynchronous and about 1/5 cases the
bgp client process them in a different order.
2023/10/06 06:22:18 BGP: [VP18N-HB5R6] VRF testVRF1001(766) is to be
deleted.
2023/10/06 06:22:18 BGP: [RH4KQ-X3CYT] VRF testVRF1001(766) is to be
disabled.
2023/10/06 06:22:18 BGP: [X8ZE0-9TS5H] VRF disable testVRF1001 id 766
2023/10/06 06:22:18 BGP: [X67AQ-923PR] Deregistering VRF 766
2023/10/06 06:22:18 BGP: [K52W0-YZ4T8] VRF Deletion:
testVRF1001(4294967295)
.. and a bit later :
2023/10/06 06:22:18 BGP: [MRXGD-9MHNX] DJERNAES: process L3VNI 1001 DEL
2023/10/06 06:22:18 BGP: [NCEPE-BKB1G][EC 33554467] Cannot process L3VNI
1001 Del - Could not find BGP instance
When the bgp vrf config is removed later it fails on the sanity check if
l3vni is removed.
if (bgp->l3vni) {
vty_out(vty, "%% Please unconfigure l3vni %u\n",
bgp->l3vni);
return CMD_WARNING_CONFIG_FAILED;
}
Solution:
=========
The solution is to make bgp cleanup the l3vni a bgp instance is going
down.
The fix:
========
The fix is to add a function in bgp_evpn.c to be responsible for for
deleting the local vni, if it should be needed, and call the function
from bgp_instance_down().
Testing:
========
Created a test, which can run in container lab that remove the vrf on
the host before removing the vrf and the bgp config form frr. Running
this test in a loop trigger the problem 18 times of 100 runs. After the
fix it did not fail.
To verify the fix a log message (which is not in the code any longer)
were used when we had a stale l3vni and needed to call
bgp_evpn_local_l3vni_del() to do the cleanup. This were hit 20 times in
100 test runs.
Signed-off-by: Kacper Kwasny <kkwasny@akamai.com>
bgpd: braces {} are not necessary for single line block
Signed-off-by: Kacper Kwasny <kkwasny@akamai.com>
Current changes deals with EVPN routes installation to zebra.
In evpn_route_select_install() we invoke evpn_zebra_install/uninstall
which sends zclient_send_message().
This is a continuation of code changes (similar to
ccfe452763) but to handle evpn part
of the code.
Ticket: #3390099
Signed-off-by: Rajasekar Raja <rajasekarr@nvidia.com>
Even if some of the attributes in bgp_path_info_extra are
not used, their memory is still allocated every time. It
cause a waste of memory.
This commit code deletes all unnecessary attributes and
changes the optional attributes to pointer storage. Memory
will only be allocated when they are actually used. After
optimization, extra info related memory is reduced by about
half(~400B -> ~200B).
Signed-off-by: Valerian_He <1826906282@qq.com>
Adds a generalized martian reimport function used for triggering a
relearn/reimport of EVPN routes that were previously filtered/deleted
as a result of a "self" check (either during import or by a martian
change handler). The MAC-VRF SoO is the first consumer of this function,
but can be expanded for use with Martian Tunnel-IPs, Interface-IPs,
Interface-MACs, and RMACs.
Signed-off-by: Trey Aspelund <taspelund@nvidia.com>
Currently we have a handler function that will walk the global EVPN
rib and unimport/remove routes matching a local IP/TIP. This generalizes
this function so that it can be re-used for other BGP Martian entry
types. Now this can be used to unimport routes when the MAC-VRF SoO is
reconfigured.
Signed-off-by: Trey Aspelund <taspelund@nvidia.com>
Add some bgp_path_info helper functions for getting the correct l3vni
label, getting the vni from the label stack, and determinging if
the mpath is D-VNI based.
Signed-off-by: Stephen Worley <sworley@nvidia.com>
Use the already existing mpls label code to store VNI
info for vxlan. VNI's are defined as labels just like mpls,
we should be using the same code for both.
This patch is the first part of that. Next we will need to
abstract the label code to not be so mpls specific. Currently
in this, we are just treating VXLAN as a label type and storing
it that way.
Signed-off-by: Stephen Worley <sworley@nvidia.com>
Gateway IP overlay index of the remote type-5 route is resolved
recursively using remote type-2 route. For the purpose of this
recursive resolution, for each L2VNI, we build a hash table of the
remote IP addresses received by remote type-2 routes.
For the topologies where overlay index resolution is not needed, we
do not need to build this remote-ip-hash.
Thus, make the recursive resolution of the overlay index conditional on
"enable-resolve-overlay-index" configuration.
router bgp 65001
bgp router-id 192.168.100.1
neighbor 10.0.1.2 remote-as 65002
!
address-family l2vpn evpn
neighbor 10.0.1.2 activate
advertise-all-vni
enable-resolve-overlay-index----------> New configuration
exit-address-family
Gateway IP overlay index will be resolved only if this configuration is present.
Signed-off-by: Ameya Dharkar <adharkar@vmware.com>
When EVPN prefix route with a gateway IP overlay index is imported into the IP
vrf at the ingress PE, BGP nexthop of this route is set to the gateway IP.
For this vrf route to be valid, following conditions must be met.
- Gateway IP nexthop of this route should be L3 reachable, i.e., this route
should be resolved in RIB.
- A remote MAC/IP route should be present for the gateway IP address in the
EVI(L2VPN table).
To check for the first condition, gateway IP is registered with nht (nexthop
tracking) to receive the reachability notifications for this IP from zebra RIB.
If the gateway IP is reachable, zebra sends the reachability information (i.e.,
nexthop interface) for the gateway IP.
This nexthop interface should be the SVI interface.
Now, to find out type-2 route corresponding to the gateway IP, we need to fetch
the VNI for the above SVI.
To do this VNI lookup effitiently, define a hashtable of struct bgpevpn with
svi_ifindex as key.
struct hash *vni_svi_hash;
An EVI instance is added to vni_svi_hash if its svi_ifindex is nonzero.
Using this hash, we obtain struct bgpevpn corresponding to the gateway IP.
For gateway IP overlay index recursive lookup, once we find the correct EVI, we
have to lookup its route table for a MAC/IP prefix. As we have to iterate the
entire route table for every lookup, this lookup is expensive. We can optimize
this lookup by adding all the remote IP addresses in a hash table.
Following hash table is defined for this purpose in struct bgpevpn
Struct hash *remote_ip_hash;
When a MAC/IP route is installed in the EVI table, it is also added to
remote_ip_hash.
It is possible to have multiple MAC/IP routes with the same IP address because
of host move scenarios. Thus, for every address addr in remote_ip_hash, we
maintain list of all the MAC/IP routes having addr as their IP address.
Following structure defines an address in remote_ip_hash.
struct evpn_remote_ip {
struct ipaddr addr;
struct list *macip_path_list;
};
A Boolean field is added to struct bgp_nexthop_cache to indicate that the
nexthop is EVPN gateway IP overlay index.
bool is_evpn_gwip_nexthop;
A flag BGP_NEXTHOP_EVPN_INCOMPLETE is added to struct bgp_nexthop_cache.
This flag is set when the gateway IP is L3 reachable but not yet resolved by a
MAC/IP route.
Following table explains the combination of L3 and L2 reachability w.r.t.
BGP_NEXTHOP_VALID and BGP_NEXTHOP_EVPN_INCOMPLETE flags
* | MACIP resolved | MACIP unresolved
*----------------|----------------|------------------
* L3 reachable | VALID = 1 | VALID = 0
* | INCOMPLETE = 0 | INCOMPLETE = 1
* ---------------|----------------|--------------------
* L3 unreachable | VALID = 0 | VALID = 0
* | INCOMPLETE = 0 | INCOMPLETE = 0
Procedure that we use to check if the gateway IP is resolvable by a MAC/IP
route:
- Find the EVI/L2VRF that belongs to the nexthop SVI using vni_svi_hash.
- Check if the gateway IP is present in remote_ip_hash in this EVI.
When the gateway IP is L3 reachable and it is also resolved by a MAC/IP route,
unset BGP_NEXTHOP_EVPN_INCOMPLETE flag and set BGP_NEXTHOP_VALID flag.
Signed-off-by: Ameya Dharkar <adharkar@vmware.com>
SVI ifindex for L2VNI is required in BGP to perform EVPN type-5 to type-2
recusrsive resolution using gateway IP overlay index.
Program this svi_ifindex in struct zebra_vni_t as well as in struct bgpevpn
Changes include:
1. Add svi_if field to struct zebra_evpn_t
2. Add svi_ifindex field to struct bgpevpn
3. When SVI (bridge or VLAN) is bound to a VxLAN interface, store it in the
zebra_evpn_t structure.
4. Add this SVI ifindex to ZEBRA_VNI_ADD
5. Store svi_ifindex in struct bgpevpn
Signed-off-by: Ameya Dharkar <adharkar@vmware.com>
Adds gateway-ip option to advertise ipv4/ipv6 unicast CLI.
dev(config-router-af)# advertise <ipv4|ipv6> unicast
<cr>
gateway-ip Specify EVPN Overlay Index
route-map route-map for filtering specific routes
When gateway-ip is specified, gateway IP field of EVPN RT-5 NLRI is filled with
the BGP nexthop of the vrf prefix being advertised.
No support for ESI overlay index yet.
Test cases:
1) advertise ipv4 unicast
2) advertise ipv4 unicast gateway-ip
3) advertise ipv6 unicast
4) advertise ipv6 unicast gateway-ip
5) Modify from no-overlay-index to gateway-ip
6) Modify from gateway-ip to no-overlay-index
7) CLI with route-map and modify route-map
Author: Sri Mohana Singamsetty <srimohans@gmail.com>
Signed-off-by: Sri Mohana Singamsetty <srimohans@gmail.com>
1. When a local ES is deleted or the ES-bond goes into bypass we treat
imported MAC-IP routes with that ES destination as remote routes instead
of sync routes. This requires a re-evaluation of the routes as
"non-local-dest" and an update to zebra.
2. When a ES is attached to an access port or the ES-bond transitions from
bypass to LACP-up we treat imported MAC-IP routes with that ES destination as
sync routes. This requires a re-evaluation of the routes as
"local-dest" and an update to zebra.
Signed-off-by: Anuradha Karuppiah <anuradhak@cumulusnetworks.com>
Host routes imported into the VRF can have a destination ES (per-VRF)
which is set up as a L3NHG for efficient failover.
Signed-off-by: Anuradha Karuppiah <anuradhak@cumulusnetworks.com>
This is the base patch that brings in support for Type-1 routes.
It includes support for -
- Ethernet Segment (ES) management
- EAD route handling
- MAC-IP (Type-2) routes with a non-zero ESI i.e. Aliasing for
active-active multihoming
- Initial infra for consistency checking. Consistency checking
is a fundamental feature for active-active solutions like MLAG.
We will try to levarage the info in the EAD-ES/EAD-EVI routes to
detect inconsitencies in access config across VTEPs attached to
the same Ethernet Segment.
Functionality Overview -
========================
1. Ethernet segments are created in zebra and associated with
access VLANs. zebra sends that info as ES and ES-EVI objects to BGP.
2. BGP advertises EAD-ES and EAD-EVI routes for the locally attached
ethernet segments.
3. Similarly BGP processes EAD-ES and EAD-EVI routes from peers
and translates them into ES-VTEP objects which are then sent to zebra
as remote ESs.
4. Each ES in zebra is associated with a list of active VTEPs which
is then translated into a L2-NHG (nexthop group). This is the ES
"Alias" entry
5. MAC-IP routes with a non-zero ESI use the alias entry created in
(4.) to forward traffic i.e. a MAC-ECMP is done to these remote-ES
destinations.
EAD route management (route table and key) -
============================================
1. Local EAD-ES routes
a. route-table: per-ES route-table
key: {RD=ES-RD, ESI, ET=0xffffffff, VTEP-IP)
b. route-table: per-VNI route-table
Not added
c. route-table: global route-table
key: {RD=ES-RD, ESI, ET=0xffffffff)
2. Remote EAD-ES routes
a. route-table: per-ES route-table
Not added
b. route-table: per-VNI route-table
key: {RD=ES-RD, ESI, ET=0xffffffff, VTEP-IP)
c. route-table: global route-table
key: {RD=ES-RD, ESI, ET=0xffffffff)
3. Local EAD-EVI routes
a. route-table: per-ES route-table
Not added
b. route-table: per-VNI route-table
key: {RD=0, ESI, ET=0, VTEP-IP)
c. route-table: global route-table
key: {RD=L2-VNI-RD, ESI, ET=0)
4. Remote EAD-EVI routes
a. route-table: per-ES route-table
Not added
b. route-table: per-VNI route-table
key: {RD=0, ESI, ET=0, VTEP-IP)
c. route-table: global route-table
key: {RD=L2-VNI-RD, ESI, ET=0)
Please refer to bgp_evpn_mh.h for info on how the data-structures are
organized.
Signed-off-by: Anuradha Karuppiah <anuradhak@cumulusnetworks.com>
Re-org only; no other code changes. This is being done to make maintanence
of MH functionality (which will have more code added to it) easy.
The code moved here was originally committed via -
'commit 50f74cf131 ("*: support for evpn type-4 route")'
Signed-off-by: Anuradha Karuppiah <anuradhak@cumulusnetworks.com>
This is the bulk part extracted from "bgpd: Convert from `struct
bgp_node` to `struct bgp_dest`". It should not result in any functional
change.
Signed-off-by: Donald Sharp <sharpd@cumulusnetworks.com>
Signed-off-by: David Lamparter <equinox@opensourcerouting.org>
Future work needs the ability to specify a
const struct prefix value. Iterate into
bgp a bit to get this started.
Signed-off-by: Donald Sharp <sharpd@cumulusnetworks.com>
Modify more code to use `const struct prefix` throughout
bgp. This is all prep work for adding an accessor function
for bgp_node to get the prefix and reduce all the places that
code needs to be touched when we get that work done.
Signed-off-by: Donald Sharp <sharpd@cumulusnetworks.com>
In L3VNI add callback parse, vrr rmac value.
For non-zero vrr mac value, use it as anycast RMAC
and svi mac as individual rmac value.
If advertise-pip is disable or vrr rmac is not present
use svi mac as anycast rmac value for all routes.
Ticket:CM-26190
Reviewed By:
Testing Done:
Signed-off-by: Chirag Shah <chirag@cumulusnetworks.com>
Evpn Primary IP advertisement feature uses
individual system IP and system MAC for prefix (type-5)
and self type-2 routes.
The PIP knob is enabled by default for bgp vrf instance.
Configuration CLI for enable/disable PIP feature knob.
User can configure PIP system IP and MAC to retain as
permanent values.
For the PIP IP, the default behavior is to accept bgp default
instance's router-id. When the default instance router-id change,
reflect PIP IP assignment.
Reflect type-5 to use system-IP and system MAC as nexthop and RMAC
values.
Ticket:CM-26190
Signed-off-by: Chirag Shah <chirag@cumulusnetworks.com>
Problem statement:
When IPv4/IPv6 prefixes are received in BGP, bgp_update function registers the
nexthop of the route with nexthop tracking module. The BGP route is marked as
valid only if the nexthop is resolved.
Even for EVPN RT-5, route should be marked as valid only if the the nexthop is
resolvable.
Code changes:
1. Add nexthop of EVPN RT-5 for nexthop tracking. Route will be marked as valid
only if the nexthop is resolved.
2. Only the valid EVPN routes are imported to the vrf.
3. When nht update is received in BGP, make sure that the EVPN routes are
imported/unimported based on the route becomes valid/invalid.
Testcases:
1. At rtr-1, advertise EVPN RT-5 with a nexthop 10.100.0.2.
10.100.0.2 is resolved at rtr-2 in default vrf.
At rtr-2, remote EVPN RT-5 should be marked as valid and should be imported into
vrfs.
2. Make the nexthop 10.100.0.2 unreachable at rtr-2
Remote EVPN RT-5 should be marked as invalid and should be unimported from the
vrfs. As this code change deals with EVPN type-5 routes only, other EVPN routes
should be valid.
3. At rtr-2, add a static route to make nexthop 10.100.0.2 reachable.
EVPN RT-5 should again become valid and should be imported into the vrfs.
Signed-off-by: Ameya Dharkar <adharkar@vmware.com>
If PIM-SM if used for BUM flooding the multicast group address can be
configured per-vxlan-device. BGP receives this config from zebra via
the L2 VNI add/update.
Sample output -
root@TORS1:~# vtysh -c "show bgp l2vpn evpn vni 1000" |grep Mcast
Mcast group: 239.1.1.100
root@TORS1:~#
Signed-off-by: Anuradha Karuppiah <anuradhak@cumulusnetworks.com>
This replaces manual checks of the flag with a wrapper macro to convey
the meaning "is evpn enabled on this vrf?"
Signed-off-by: Tuetuopay <tuetuopay@me.com>
Sponsored-by: Scaleway
This makes the instance bearing the advertise-all-vni config option
register to zebra as the EVPN one, forwarding it the option.
Signed-off-by: Tuetuopay <tuetuopay@me.com>
Sponsored-by: Scaleway
With leaking of IPv4 or IPv6 unicast routes whose source is a EVPN
type-2 or type-5 route between VRFs, the determination of whether
the route's source is EVPN has to be made recursively. This is used
during route install to pass along appropriate parameters to zebra.
Signed-off-by: Vivek Venkatraman <vivek@cumulusnetworks.com>
Reviewed-by: Anuradha Karuppiah <anuradhak@cumulusnetworks.com>
Reviewed-by: Donald Sharp <sharpd@cumulusnetworks.com>
Refine check on whether a route can be injected into EVPN to allow
EVPN-sourced routes to be injected back into another instance.
Signed-off-by: Vivek Venkatraman <vivek@cumulusnetworks.com>
Reviewed-by: Anuradha Karuppiah <anuradhak@cumulusnetworks.com>
Reviewed-by: Donald Sharp <sharpd@cumulusnetworks.com>
IPv4 or IPv6 unicast routes which are imported from EVPN routes
(type-2 or type-5) and installed in a BGP instance and then leaked
do not need any nexthop tracking, as any tracking should happen in
the source instance.
Signed-off-by: Vivek Venkatraman <vivek@cumulusnetworks.com>
Reviewed-by: Anuradha Karuppiah <anuradhak@cumulusnetworks.com>
Reviewed-by: Donald Sharp <sharpd@cumulusnetworks.com>
In the case of EVPN symmetric routing, the tenant VRF is associated with
a VNI that is used for routing and commonly referred to as the L3 VNI or
VRF VNI. Corresponding to this VNI is a VLAN and its associated L3 (IP)
interface (SVI). Overlay next hops (i.e., next hops for routes in the
tenant VRF) are reachable over this interface.
https://tools.ietf.org/html/draft-ietf-bess-evpn-prefix-advertisement
section 4.4 provides additional description of the above constructs.
The implementation currently derives this L3 interface for EVPN tenant
routes using special code that looks at route flags. This patch
exchanges the L3 interface between zebra and bgpd as part of the L3-VNI
exchange in order to eliminate some this special code.
Signed-off-by: Vivek Venkatraman <vivek@cumulusnetworks.com>
Reviewed-by: Anuradha Karuppiah <anuradhak@cumulusnetworks.com>
Reviewed-by: Donald Sharp <sharpd@cumulusnetworks.com>
When an inactive-neigh delete is rxed bgp will not have a local path to
remove (and re-run path selection). Instead it simply re-installs the
current best remote path if any.
Ticket: CM-23018
Testing Done: evpn-min
Signed-off-by: Anuradha Karuppiah <anuradhak@cumulusnetworks.com>
Add the '[no] flood <disable|head-end-replication>' command
to the l2vpn evpn afi/safi sub commands for bgp. This command
when entered as 'flood disable' will turn off type 3 route
generation for the transmittal of the type 3 route necessary
for BUM replication on the remote VTEP. Additionally it will
turn off the BUM handling via the new zebra command,
ZEBRA_VXLAN_FLOOD_CONTROL.
Signed-off-by: Vivek Venkatraman <vivek@cumulusnetworks.com>
Signed-off-by: Donald Sharp <sharpd@cumulusnetworks.com>
Do a straight conversion of `struct bgp_info` to `struct bgp_path_info`.
This commit will setup the rename of variables as well.
This is being done because `struct bgp_info` is not descriptive
of what this data actually is. It is path information for routes
that we keep to build the actual routes nexthops plus some extra
information.
Signed-off-by: Donald Sharp <sharpd@cumulusnetworks.com>
Implement procedures similar to what is specified in
https://tools.ietf.org/html/draft-malhotra-bess-evpn-irb-extended-mobility
in order to support extended mobility scenarios in EVPN. These are scenarios
where a host/VM move results in a different (MAC,IP) binding from earlier.
For example, a host with an address assignment (IP1, MAC1) moves behind a
different PE (VTEP) and has an address assignment of (IP1, MAC2) or a host
with an address assignment (IP5, MAC5) has a different assignment of (IP6,
MAC5) after the move. Note that while these are described as "move" scenarios,
they also cover the situation when a VM is shut down and a new VM is spun up
at a different location that reuses the IP address or MAC address of the
earlier instance, but not both. Yet another scenario is a MAC change for an
attached host/VM i.e., when the MAC of an attached host changes from MAC1 to
MAC2. This is necessary because there may already be a non-zero sequence
number associated with MAC2. Also, even though (IP, MAC1) is withdrawn before
(IP, MAC2) is advertised, they may propagate through the network differently.
The procedures continue to rely on the MAC mobility extended community
specified in RFC 7432 and already supported by the implementation, but
augment it with a inheritance mechanism that understands the relationship
of the host MACIP (ARP/neighbor table entry) to the underlying MAC (MAC
forwarding database entry). In FRR, this relationship is understood by the
zebra component which doubles as the "host mobility manager", so the MAC
mobility sequence numbers are determined through interaction between bgpd
and zebra.
Signed-off-by: Vivek Venkatraman <vivek@cumulusnetworks.com>
Reviewed-by: Donald Sharp <sharpd@cumulusnetworks.com>
Reviewed-by: Anuradha Karuppiah <anuradhak@cumulusnetworks.com>
