TI-LFA is a modern fast-reroute (FRR) solution that leverages Segment
Routing to pre-compute backup nexthops for all destinations in the
network, helping to reduce traffic restoration times whenever a
failure occurs. The backup nexthops are expected to be installed
in the FIB so that they can be activated as soon as a failure
is detected, making sub-50ms recovery possible (assuming an
hierarchical FIB).
TI-LFA is a huge step forward compared to prior IP-FRR solutions,
like classic LFA and Remote LFA, as it guarantees 100% coverage
for all destinations. This is possible thanks to the source routing
capabilities of SR, which allows the backup nexthops to steer traffic
around the failures (using as many SIDs as necessary). In addition
to that, the repair paths always follow the post-convergence SPF
tree, which prevents transient congestions and suboptimal routing
from happening.
Deploying TI-LFA is very simple as it only requires a single
configuration command for each interface that needs to be protected
(both link protection and node protection are available). In addition
to IPv4 and IPv6 routes, SR Prefix-SIDs and Adj-SIDs are also
protected by the backup nexthops computed by the TI-LFA algorithms.
Signed-off-by: Renato Westphal <renato@opensourcerouting.org>
1. Added isis with different vrf and it's dependecies.
2. Added new vrf leaf in yang.
3. A minor change for IF_DOWN_FROM_Z passing argrument is
replaced with ifp pointer in api "isis_if_delete_hook()".
4. Minor fix in the isisd spf unit test.
Co-authored-by: Kaushik <kaushik@niralnetworks.com>"
Signed-off-by: harios_niral <hari@niralnetworks.com>
Now that the IS-IS SPF code is more modular, write some unit tests
for it.
This commit includes a new test program called "test_isis_spf" which
can load any test topology (there are 13 different ones available)
and run SPF on any desired node. In the future this same test program
and topologies will also be used to test reverse SPF and TI-LFA.
The "test_common.c" file contains helper functions used to parse the
topology descriptions from "test_topologies.c" into LSP databases
that can be used as an input to the SPF code.
This commit also introduces the F_ISIS_UNIT_TEST flag which is used
to prevent the IS-IS code from scheduling any event when running
under the context of an unit test.
Signed-off-by: Renato Westphal <renato@opensourcerouting.org>
* Bring back some consts that were removed;
* Replace ALL_LIST_ELEMENTS by ALL_LIST_ELEMENTS_RO whenever
possible;
* Fix some CLI return values;
* Remove some unnecessary initializations.
Signed-off-by: Renato Westphal <renato@opensourcerouting.org>
1. Created a structure "isis master".
2. All the changes are related to handle ISIS with different vrf.
3. A new variable added in structure "isis" to store the vrf name.
4. The display commands for isis is changed to support different VRFs.
Signed-off-by: Kaushik <kaushik@niralnetworks.com>
This should simplify all code that needs to iterate over all
adjacencies of a given area (iterating over all adjacencies of all
circuits is cumbersome).
While here, repurpose isis_adj_exists() into a lookup function,
making it more generally useful.
Signed-off-by: Renato Westphal <renato@opensourcerouting.org>
The global isis structure can't be created/destroyed using the CLI,
so there's no need to define a QOBJ for it.
Signed-off-by: Renato Westphal <renato@opensourcerouting.org>
Make that function accept an IS-IS area pointer instead of an
area name, making it more in line with the rest of the code base
(*delete() functions shouldn't perform lookups internally).
Signed-off-by: Renato Westphal <renato@opensourcerouting.org>
Unfortunately as the topotests show a fast recovery after failure
detection due to BFD is currently not possible because of the following
issue:
There are multiple scheduling mechanisms within isisd to prevent
overload situations. Regarding our problem these two are important:
* scheduler for regenerating ISIS Link State PDUs scheduler for managing
* consecutive SPF calculations
In fact both schedulers are coupled, the first one triggers the second
one, which again is triggered by isis_adj_state_change (which again is
triggered by a BFD 'down' message). The re-calculation of SPF paths
finally triggers updates in zebra for the RIB.
Both schedulers work as a throttle, e.g. they allow the regeneration of
Link State PDUs or a re-calculation for SPF paths only once within a
certain time interval which is configurable (and by default different!).
This means that a request can go through the first scheduler but might
still be 'stuck' at the second one for a while. Or a request can be
'stuck' at the first scheduler even though the second one is ready. This
also explains the 'random' behaviour one can observe testing since a
'fast' recovery is only possible if both schedulers are ready to process
this request.
Note that the solution in this commit is 'thread safe' in the sense that
both schedulers use the same thread master such that the introduced
flags are only used exactly one time (and one after another) for a
'fast' execution.
Further there are some irritating comments and logs which I partially
removed. They seems to be not valid anymore due to changes in thread
management (or they were never valid in the first place).
Signed-off-by: GalaxyGorilla <sascha@netdef.org>
This is an implementation of the IS-IS SR draft [1] for FRR.
The following features are supported:
* IPv4 and IPv6 Prefix-SIDs;
* IPv4 and IPv6 Adj-SIDs and LAN-Adj-SIDs;
* Index and absolute labels;
* The no-php and explicit-null Prefix-SID flags;
* Full integration with the Label Manager.
Known limitations:
* No support for Anycast-SIDs;
* No support for the SID/Label Binding TLV (required for LDP interop).
* No support for persistent Adj-SIDs;
* No support for multiple SRGBs.
[1] draft-ietf-isis-segment-routing-extensions-25
Signed-off-by: Olivier Dugeon <olivier.dugeon@orange.com>
Signed-off-by: Renato Westphal <renato@opensourcerouting.org>
isisd implements an optimization that allows multiple routes to
share the same nexthop (using a refcount) in order to save memory.
Now that SR support is coming, however, it will be necessary to
embed additional SR-related information inside the isis_nexthop
structure. But this can only be done if the nexthops aren't shared
among routes anymore.
Removing this memory optimization should have minimal impact since
the isis_nexthop structure is really small. On large networks with
thousands of routes, the memory saving would be in the order of a
few kilobytes. Not something we should be concerned about nowadays.
Signed-off-by: Renato Westphal <renato@opensourcerouting.org>
Rearrange the isisd northbound callbacks as following:
* isis_nb.h: prototypes of all northbound callbacks.
* isis_nb.c: definition of all northbound callbacks and their
associated YANG data paths.
* isis_nb_config.c: implementation of YANG configuration nodes.
* isis_nb_state.c: implementation of YANG state nodes.
* isis_nb_notifications.c: implementation of YANG notifications.
This should help to keep to code more organized and easier to
maintain.
No behavior changes intended.
Signed-off-by: Renato Westphal <renato@opensourcerouting.org>
This unification allows us to write code that works for both IPv4 and
IPv6, reducing duplication.
Signed-off-by: Renato Westphal <renato@opensourcerouting.org>
Historically, isisd has been carrying around its own red-black tree to
manage its LSP DB in. This replaces that with the newly-added
DECLARE_RBTREE_*. This allows completely removing the dict_* code.
Signed-off-by: David Lamparter <equinox@diac24.net>
Solve issue #4032
- Change MPLS-TE from global to per Area
- Add new mpls_te_area structure to area in replacement of global variable
isisMPLS_TE
- Move mpls-te from global to instance in frr-isisd.yang
- Change code in isis_te.c, isis_northbound.c, isis_cli.c, isis_pdu.c,
isis_lsp.c and isis_zebra.c accordingly
Signed-off-by: Olivier Dugeon <olivier.dugeon@orange.com>
- Change MPLS-TE from global to per Area
- Add new mpls_te_area structure to area in replacement of global variable
isisMPLS_TE
- Move mpls-te frmo global to instance in frr-isisd.yang
- Change code in isis_te.c, isis_northbound.c, isis_cli.c, isis_pdu.c,
isis_lsp.c and isis_zebra.c accordingly
Signed-off-by: Olivier Dugeon <olivier.dugeon@orange.com>
Note that we do not return the actual tlv_type and offset
of the erroneous TLV. This is because unpacking tlvs currently
uses a chain of function calls, where the notification can only
be sent at the start of the chain, but the tlv_type and offset
information are only available at the end. Unless we change the
code to propagate those values, we have no way to feed them to
the notification. So these leafs are not generated.
Signed-off-by: Emanuele Di Pascale <emanuele@voltanet.io>
the original isisd code did not distinguish between
authentication_failure and authentication_type_failure, so
additional code had to be added to differentiate between the two
and to return the raw_pdu as requested by the IETF YANG model.
Signed-off-by: Emanuele Di Pascale <emanuele@voltanet.io>
Note that the original IETF YANG model also included
a requirement to throttle such notifications so that they would
not be sent more often than once every 5 seconds. I did not
implement any throttling mechanism yet, mostly because I am
not sure whether this limit should apply to the entire isis daemon,
to each area, to each neighbor etc.
Signed-off-by: Emanuele Di Pascale <emanuele@voltanet.io>
However it is not currently called anywhere, as I could not find a
place in the code where it felt appropriate.
Signed-off-by: Emanuele Di Pascale <emanuele@voltanet.io>
Note that some of the validation checks that were previously
executed in the code have been moved to the YANG model.
Signed-off-by: Emanuele Di Pascale <emanuele@voltanet.io>
These are complex commands to retrofit, partly due to the number of
different callbacks they touch. Additionally, in FRR adding
an interface to an IS-IS area that does not exist also creates that
area. To make sure that this behavior is kept, while at the same
time keeping the northbound api consistent, we need to take extra
care to call the appropriate callbacks to update the YANG tree.
Note that many callbacks rely on the existence of the corresponding
IS-IS area; when these callbacks are joined together in a single
transaction, we need to ensure that the area creation is performed
first, or the config will fail. For this reason, the isis instance
create callback has been given a slightly lower priority than the
others.
Signed-off-by: Emanuele Di Pascale <emanuele@voltanet.io>
Finding an LSP by its id is useful not only for the
`show isis database` command.
So move it out into its own function to make it reusable.
Signed-off-by: Christian Franke <chris@opensourcerouting.org>
