IPv6 Compliance RFC4861: Redirected On-link: Valid (Hosts Only) [v6LC.2.3.1 Part C]

[LiveFreeAndRoam]

systemd version the issue has been seen with

256

Used distribution

Ubuntu 23

Linux kernel version used

6.5.0-17-generic

CPU architectures issue was seen on

x86_64

Component

systemd-networkd

Expected behaviour you didn't see

RA Prefix Cleanup is NOT cleaning up

This issue shows up in many tests, especially those that test REDIRECT. So I'll use this REDIRECT test (2.3.1c) as the basis for this issue.

Test v6LC.2.3.1: Redirected On-link: Valid (Hosts Only)

Purpose: Verify that a host properly processes valid Redirect messages when redirected on-link: (no Redirect Pkt Option)
Reference: RFC 4861, Section 4.6.1, 4.6.3, and 8.3

Network Configuration

       TR1
        |
    +---+---+
    |       |
   TN1     HUT

^{Legend: TN1=Test Node, TR1=Test Router, HUT=Host Under Test
TR1 Pfx: 2001:2:0:1000/64
TN1 GA: 2001:2:0:1001:200:10ff:fe10:1180 (offlink address, but is physically onlink)
HUT GA: 2001:2:0:1000:a00:27ff:fe1a:432/64}

Procedure

Step	Action	Expected Behavior of HUT(1)
1	TR1 forwards Echo request Src="TN1 Offlink GA" to HUT GA(2).	HUT sends Echo reply to TR1 as first hop.
2	TR1 sends Redirect Dst="TN1 GA" Target="TN1 GA" to HUT.
3	TR1 forwards Echo request Src="TN1 Offlink GA" to HUT GA.	HUT sends NS for TN1's GA and Echo reply to TN1 on-link.

• (1) - Host Under Test
• (2) - Global Address

Unexpected behaviour you saw

There are two steps required to cause this failure:

1. The first time this test runs, networkd recieves a REDIRECT message targetting TN1 GA and it updates the routing table and the test passes.
2. Subsequent runs fail, because the REDIRECT route persists. When we next ping the HUT from TN1 GA, this causes networkd to send NS for TN1 GA, when the test is expecting an Echo Reply.

Comparing networkd behaviour with the native kernel behaviour, you can see that the kernel does NOT add a redirect route to the routing table. So it avoids this issue.

Between test runs, if I manually delete the redirect route, the next test passes. ie. running this command after each test results in the next test passing:

sudo ip -6 r del 2001:2:0:1001:200:10ff:fe10:1180 dev enp0s9

Watch Systemd-Networkd Routing Table

$ old=""; while :; do out=$(ip -6 r show dev enp0s9); new=$(echo "$out" | sed 's/expires.*sec //'); [ "$new" != "$old" ] && date +"%F %T.%N:%n""${out}%n"; old="$new"; sleep 1; done

### 1. Initial state
2024-04-28 09:03:32.687174870:
fe80::/64 proto kernel metric 256 pref medium

### 2. Received RA Prefix=2001:2:0:1000::/64
2024-04-28 09:03:37.782118076:
2001:2:0:1000::/64 proto ra metric 1024 expires 65534sec pref medium
fe80::/64 proto kernel metric 256 pref medium
default via fe80::200:10ff:fe10:1060 proto ra metric 1024 expires 8999sec mtu 1500 pref medium

### 3. Received REDIRECT request targetting 2001:2:0:1001:200:10ff:fe10:1180
### *** Why was a host route added (2001:2:0:1001:200:10ff:fe10:1180)???
2024-04-28 09:03:45.892788195:
2001:2:0:1000::/64 proto ra metric 1024 expires 65526sec pref medium
2001:2:0:1001:200:10ff:fe10:1180 proto redirect metric 1024 pref medium
fe80::/64 proto kernel metric 256 pref medium
default via fe80::200:10ff:fe10:1060 proto ra metric 1024 expires 8991sec mtu 1500 pref medium

### 4. Received RA Prefix=2001:2:0:1000::/64 Lifetime=0, Router Lifetime=0
### Redirect route persists, causing next test to fail.
2024-04-28 09:03:46.909014218:
2001:2:0:1001:200:10ff:fe10:1180 proto redirect metric 1024 pref medium
fe80::/64 proto kernel metric 256 pref medium

Watch Kernel Native Routing Table

NOTE: This test was performed with networkd stopped and sycctl accept_ra=2, so this shows how the kernel native solution behaves.

$ old=""; while :; do out=$(ip -6 r show dev enp0s9); new=$(echo "$out" | sed 's/expires.*sec //'); [ "$new" != "$old" ] && date +"%F %T.%N:%n""${out}%n"; old="$new"; sleep 1; done

### 1. Initial State
2024-04-28 09:30:47.279772318:
fe80::/64 proto kernel metric 256 pref medium

### 2. Received RA Prefix=2001:2:0:1000::/64 > new route is added
2024-04-28 09:30:53.372220636:
2001:2:0:1000::/64 proto kernel metric 256 expires 65534sec pref medium
fe80::/64 proto kernel metric 256 pref medium
default via fe80::200:10ff:fe10:1060 proto ra metric 1024 expires 8999sec hoplimit 64 pref medium

### 3. Received REDIRECT request targetting 2001:2:0:1001:200:10ff:fe10:1180
### NOTE: Unlike networkd, there is no "redirect" route added.

### 4. Received RA Prefix=2001:2:0:1000::/64 Lifetime=0, Router Lifetime=0
2024-04-28 09:31:03.515867947:
fe80::/64 proto kernel metric 256 pref medium

Steps to reproduce the problem

For reference only: Previous issue relating to Redirect is #31438.

Run the test twice. IF using tcpreplay, run the "pass" PCAP twice. The 2nd time it will fail.

v6LC_2_3_01c.zip

Additional program output to the terminal or log subsystem illustrating the issue

#########################################
# Debug LOG from first test (PASSES)    #
# See below for 2nd test where it fails #
#########################################
enp0s9: NDISC: Received Router Advertisement from fe80::200:10ff:fe10:1060: flags=0x00(null), preference=medium, lifetime=2h 30min
enp0s9: NDISC: Invoking callback for 'router' event.
enp0s9: Requesting NDisc route (n/a): dst: n/a, src: n/a, gw: fe80::200:10ff:fe10:1060, prefsrc: n/a, table: main(254), priority: 1024, proto: ra, scope: global, type: unicast, flags: n/a
Setting '/proc/sys/net/ipv6/neigh/enp0s9/base_reachable_time_ms' to '30000'
No change in value '30000', suppressing write
Setting '/proc/sys/net/ipv6/neigh/enp0s9/retrans_time_ms' to '1000'
No change in value '1000', suppressing write
Setting '/proc/sys/net/ipv6/conf/enp0s9/hop_limit' to '64'
No change in value '64', suppressing write
Setting '/proc/sys/net/ipv6/conf/enp0s9/mtu' to '1500'
No change in value '1500', suppressing write
enp0s9: Requesting NDisc route (n/a): dst: 2001:2:0:1000::/64, src: n/a, gw: n/a, prefsrc: n/a, table: main(254), priority: 1024, proto: ra, scope: global, type: unicast, flags: n/a
enp0s9: Requesting NDisc address (configured): 2001:2:0:1000:a00:27ff:fe1a:432/64 (valid for 18h 12min 14s, preferred for 18h 12min 14s), flags: manage-temporary-address,no-prefixroute, scope: global
enp0s9: Setting SLAAC addresses and router.
enp0s9: State changed: configured -> configuring
Sent message type=signal sender=n/a destination=n/a path=/org/freedesktop/network1/link/_34 interface=org.freedesktop.DBus.Properties member=PropertiesChanged cookie=34 reply_cookie=0 signature=sa{sv}as error-name=n/a error-message=n/a
enp0s9: link_check_ready(): dynamic addressing protocols are enabled but none of them finished yet.
enp0s9: Configuring NDisc route (requesting): dst: n/a, src: n/a, gw: fe80::200:10ff:fe10:1060, prefsrc: n/a, table: main(254), priority: 1024, proto: ra, scope: global, type: unicast, flags: n/a
enp0s9: Configuring NDisc route (requesting): dst: 2001:2:0:1000::/64, src: n/a, gw: n/a, prefsrc: n/a, table: main(254), priority: 1024, proto: ra, scope: global, type: unicast, flags: n/a
enp0s9: Configuring NDisc address (requesting,configured): 2001:2:0:1000:a00:27ff:fe1a:432/64 (valid for 18h 12min 14s, preferred for 18h 12min 14s), flags: manage-temporary-address,no-prefixroute, scope: global
enp0s9: Received new NDisc route (configured): dst: n/a, src: n/a, gw: fe80::200:10ff:fe10:1060, prefsrc: n/a, table: main(254), priority: 1024, proto: ra, scope: global, type: unicast, flags: n/a
enp0s9: ndisc_check_ready(): SLAAC addresses and routes are not set.
enp0s9: Received new NDisc route (configured): dst: 2001:2:0:1000::/64, src: n/a, gw: n/a, prefsrc: n/a, table: main(254), priority: 1024, proto: ra, scope: global, type: unicast, flags: n/a
enp0s9: ndisc_check_ready(): SLAAC addresses and routes are not set.
enp0s9: Received updated NDisc address (configured): 2001:2:0:1000:a00:27ff:fe1a:432/64 (valid for 18h 12min 14s, preferred for 18h 12min 14s), flags: manage-temporary-address,no-prefixroute, scope: global
enp0s9: link_check_ready(): dynamic addressing protocols are enabled but none of them finished yet.
enp0s9: SLAAC addresses and routes set.
enp0s9: link_check_ready(): IPv4LL:no DHCPv4:no DHCPv6:no DHCP-PD:no NDisc:yes
enp0s9: State changed: configuring -> configured
Sent message type=signal sender=n/a destination=n/a path=/org/freedesktop/network1/link/_34 interface=org.freedesktop.DBus.Properties member=PropertiesChanged cookie=35 reply_cookie=0 signature=sa{sv}as error-name=n/a error-message=n/a
enp0s9: NDISC: Received Neighbor Advertisement from fe80::200:10ff:fe10:1060: Router=yes, Solicited=yes, Override=no
enp0s9: NDISC: Invoking callback for 'neighbor' event.
enp0s9: NDISC: Received Redirect message from fe80::200:10ff:fe10:1060: Target=2001:2:0:1001:200:10ff:fe10:1180, Destination=2001:2:0:1001:200:10ff:fe10:1180
enp0s9: NDISC: Invoking callback for 'redirect' event.
enp0s9: Requesting NDisc route (n/a): dst: 2001:2:0:1001:200:10ff:fe10:1180/128, src: n/a, gw: n/a, prefsrc: n/a, table: main(254), priority: 1024, proto: redirect, scope: global, type: unicast, flags: n/a
enp0s9: Configuring NDisc route (requesting): dst: 2001:2:0:1001:200:10ff:fe10:1180/128, src: n/a, gw: n/a, prefsrc: n/a, table: main(254), priority: 1024, proto: redirect, scope: global, type: unicast, flags: n/a
enp0s9: Received new NDisc route (configured): dst: 2001:2:0:1001:200:10ff:fe10:1180/128, src: n/a, gw: n/a, prefsrc: n/a, table: main(254), priority: 1024, proto: redirect, scope: global, type: unicast, flags: n/a
enp0s9: SLAAC addresses and routes set.
ICMPv6: Received a packet from neither link-local nor null address.
enp0s9: NDISC: Failed to receive ICMPv6 packet, ignoring: Cannot assign requested address
enp0s9: NDISC: Received Router Advertisement from fe80::200:10ff:fe10:1060: flags=0x00(null), preference=medium, lifetime=0
enp0s9: NDISC: Invoking callback for 'router' event.
enp0s9: Removing NDisc route (configured): dst: n/a, src: n/a, gw: fe80::200:10ff:fe10:1060, prefsrc: n/a, table: main(254), priority: 1024, proto: ra, scope: global, type: unicast, flags: n/a
enp0s9: Removing NDisc route (configured): dst: 2001:2:0:1000::/64, src: n/a, gw: n/a, prefsrc: n/a, table: main(254), priority: 1024, proto: ra, scope: global, type: unicast, flags: n/a
enp0s9: Forgetting removed NDisc route (n/a): dst: n/a, src: n/a, gw: fe80::200:10ff:fe10:1060, prefsrc: n/a, table: main(254), priority: 1024, proto: ra, scope: global, type: unicast, flags: n/a
enp0s9: Forgetting removed NDisc route (n/a): dst: 2001:2:0:1000::/64, src: n/a, gw: n/a, prefsrc: n/a, table: main(254), priority: 1024, proto: ra, scope: global, type: unicast, flags: n/a
enp0s9: NDISC: Received Neighbor Advertisement from fe80::200:10ff:fe10:1060: Router=yes, Solicited=no, Override=yes
enp0s9: NDISC: Invoking callback for 'neighbor' event.
Sent message type=signal sender=n/a destination=n/a path=/org/freedesktop/network1/link/_33 interface=org.freedesktop.DBus.Properties member=PropertiesChanged cookie=36 reply_cookie=0 signature=sa{sv}as error-name=n/a error-message=n/a
Sent message type=signal sender=n/a destination=n/a path=/org/freedesktop/network1/link/_33 interface=org.freedesktop.DBus.Properties member=PropertiesChanged cookie=37 reply_cookie=0 signature=sa{sv}as error-name=n/a error-message=n/a

######################################
# Debug LOG from second test (FAILS) #
######################################
enp0s9: NDISC: Received Router Advertisement from fe80::200:10ff:fe10:1060: flags=0x00(null), preference=medium, lifetime=2h 30min
enp0s9: NDISC: Invoking callback for 'router' event.
enp0s9: Requesting NDisc route (n/a): dst: n/a, src: n/a, gw: fe80::200:10ff:fe10:1060, prefsrc: n/a, table: main(254), priority: 1024, proto: ra, scope: global, type: unicast, flags: n/a
Setting '/proc/sys/net/ipv6/neigh/enp0s9/base_reachable_time_ms' to '30000'
No change in value '30000', suppressing write
Setting '/proc/sys/net/ipv6/neigh/enp0s9/retrans_time_ms' to '1000'
No change in value '1000', suppressing write
Setting '/proc/sys/net/ipv6/conf/enp0s9/hop_limit' to '64'
No change in value '64', suppressing write
Setting '/proc/sys/net/ipv6/conf/enp0s9/mtu' to '1500'
No change in value '1500', suppressing write
enp0s9: Requesting NDisc route (n/a): dst: 2001:2:0:1000::/64, src: n/a, gw: n/a, prefsrc: n/a, table: main(254), priority: 1024, proto: ra, scope: global, type: unicast, flags: n/a
enp0s9: Requesting NDisc address (configured): 2001:2:0:1000:a00:27ff:fe1a:432/64 (valid for 18h 12min 14s, preferred for 18h 12min 14s), flags: manage-temporary-address,no-prefixroute, scope: global
enp0s9: Setting SLAAC addresses and router.
enp0s9: State changed: configured -> configuring
Sent message type=signal sender=n/a destination=n/a path=/org/freedesktop/network1/link/_34 interface=org.freedesktop.DBus.Properties member=PropertiesChanged cookie=38 reply_cookie=0 signature=sa{sv}as error-name=n/a error-message=n/a
enp0s9: link_check_ready(): dynamic addressing protocols are enabled but none of them finished yet.
enp0s9: Configuring NDisc route (requesting): dst: n/a, src: n/a, gw: fe80::200:10ff:fe10:1060, prefsrc: n/a, table: main(254), priority: 1024, proto: ra, scope: global, type: unicast, flags: n/a
enp0s9: Configuring NDisc route (requesting): dst: 2001:2:0:1000::/64, src: n/a, gw: n/a, prefsrc: n/a, table: main(254), priority: 1024, proto: ra, scope: global, type: unicast, flags: n/a
enp0s9: Configuring NDisc address (requesting,configured): 2001:2:0:1000:a00:27ff:fe1a:432/64 (valid for 18h 12min 14s, preferred for 18h 12min 14s), flags: manage-temporary-address,no-prefixroute, scope: global
enp0s9: Received new NDisc route (configured): dst: n/a, src: n/a, gw: fe80::200:10ff:fe10:1060, prefsrc: n/a, table: main(254), priority: 1024, proto: ra, scope: global, type: unicast, flags: n/a
enp0s9: ndisc_check_ready(): SLAAC addresses and routes are not set.
enp0s9: Received new NDisc route (configured): dst: 2001:2:0:1000::/64, src: n/a, gw: n/a, prefsrc: n/a, table: main(254), priority: 1024, proto: ra, scope: global, type: unicast, flags: n/a
enp0s9: ndisc_check_ready(): SLAAC addresses and routes are not set.
enp0s9: Received updated NDisc address (configured): 2001:2:0:1000:a00:27ff:fe1a:432/64 (valid for 18h 12min 14s, preferred for 18h 12min 14s), flags: manage-temporary-address,no-prefixroute, scope: global
enp0s9: link_check_ready(): dynamic addressing protocols are enabled but none of them finished yet.
enp0s9: SLAAC addresses and routes set.
enp0s9: link_check_ready(): IPv4LL:no DHCPv4:no DHCPv6:no DHCP-PD:no NDisc:yes
enp0s9: State changed: configuring -> configured
Sent message type=signal sender=n/a destination=n/a path=/org/freedesktop/network1/link/_34 interface=org.freedesktop.DBus.Properties member=PropertiesChanged cookie=39 reply_cookie=0 signature=sa{sv}as error-name=n/a error-message=n/a
enp0s9: NDISC: Received Neighbor Advertisement from fe80::200:10ff:fe10:1060: Router=yes, Solicited=yes, Override=no
enp0s9: NDISC: Invoking callback for 'neighbor' event.
ICMPv6: Received a packet from neither link-local nor null address.
enp0s9: NDISC: Failed to receive ICMPv6 packet, ignoring: Cannot assign requested address
enp0s9: NDISC: Received Router Advertisement from fe80::200:10ff:fe10:1060: flags=0x00(null), preference=medium, lifetime=0
enp0s9: NDISC: Invoking callback for 'router' event.
enp0s9: Removing NDisc route (configured): dst: n/a, src: n/a, gw: fe80::200:10ff:fe10:1060, prefsrc: n/a, table: main(254), priority: 1024, proto: ra, scope: global, type: unicast, flags: n/a
enp0s9: Removing NDisc route (configured): dst: 2001:2:0:1000::/64, src: n/a, gw: n/a, prefsrc: n/a, table: main(254), priority: 1024, proto: ra, scope: global, type: unicast, flags: n/a
enp0s9: Forgetting removed NDisc route (n/a): dst: n/a, src: n/a, gw: fe80::200:10ff:fe10:1060, prefsrc: n/a, table: main(254), priority: 1024, proto: ra, scope: global, type: unicast, flags: n/a
enp0s9: NDISC: Received Neighbor Advertisement from fe80::200:10ff:fe10:1060: Router=yes, Solicited=no, Override=yes
enp0s9: NDISC: Invoking callback for 'neighbor' event.
enp0s9: Forgetting removed NDisc route (n/a): dst: 2001:2:0:1000::/64, src: n/a, gw: n/a, prefsrc: n/a, table: main(254), priority: 1024, proto: ra, scope: global, type: unicast, flags: n/a

[yuwata]

So, I may misunderstand how Redirect message should be handled. If running with accept_ra=2, how kernel handles Redirect messages? What kind of entry is added to handle the subsequent echo packet in the expected way?

[LiveFreeAndRoam]

Another possibility is that when the RA advertises a Prefix with Lifetime=0, then all routes with that prefix (including Redirect routes) get deleted. I'm not yet sure what the RFCs say about that

[LiveFreeAndRoam]

I beilieve I have collected the evidence to direct a solution here. Please let me know your thoughts...

The key question is, what mechanism is expected to remove a REDIRECT route?

When using the native kernel (6.5.0-26), i.e. accept_ra=2 and networkd is stopped, the REDIRECT route is removed by these events (also see the output below):

1. Timeout of sysctl net.ipv6.route.gc_interval
2. When the target's address prefix expires
3. When RA sets Prefix Lifetime=0 (instant expiry of the prefix)

Having networkd behave the same way would address the issues I've been seeing here. Is it possible to modify networkd to match the kernel's behaviour?

BTW: I could not find a definitive statement in an RFC about the removal of REDIRECT routes.

Route to TN1: ip r get 2001:2:0:1001:200:10ff:fe10:1180

old=""; while :; do new=$(ip r get 2001:2:0:1001:200:10ff:fe10:1180 2>&1); [ "$new" != "$old" ] && date +"%F %T.%N:%n""${new}%n"; old="$new"
; sleep 0.1; done

### 1. Initial state, no routes to TN1
2024-04-29 17:04:46.723106907:
RTNETLINK answers: Network is unreachable

### 2. RA Setup Prefix=2001:2:0:1001/64 Received.  Access TN1 via TR1
2024-04-29 17:07:02.619853375:
2001:2:0:1001:200:10ff:fe10:1180 from :: via fe80::200:10ff:fe10:1060 dev enp0s9 proto ra src 2001:2:0:1000:a00:27ff:fe1a:432 metric 1024 hoplimit 64 pref medium

### 3. REDIRECT Received - Access TN1 via interface enp0s9
2024-04-29 17:07:11.023512057:
2001:2:0:1001:200:10ff:fe10:1180 from :: dev enp0s9 src 2001:2:0:1000:a00:27ff:fe1a:432 metric 1024 hoplimit 64 pref medium

### 4. Timeout 52s after REDIRECT received (Timeout controlled by: sysctl net.ipv6.route.gc_interval)
2024-04-29 17:08:03.612010190:
2001:2:0:1001:200:10ff:fe10:1180 from :: via fe80::200:10ff:fe10:1060 dev enp0s9 proto ra src 2001:2:0:1000:a00:27ff:fe1a:432 metric 1024 hoplimit 64 pref medium

### 5. RA Clear Prefix Lifetime=0, Redirect is also cleared when prefix expires or its lifetime is set to 0.
2024-04-29 17:18:10.615051971:
RTNETLINK answers: Network is unreachable

[LiveFreeAndRoam]

Here is the RFC content that describes when to delete routes. The conclusion I draw from this is that the REDIRECT route must be removed when the Prefix expires. Extract below:

RFC4861, section 6.3.5: Timing out Prefixes and Default Routers

Whenever the invalidation timer expires for a Prefix List entry, that
entry is discarded. No existing Destination Cache entries need be
updated, however. Should a reachability problem arise with an
existing Neighbor Cache entry, Neighbor Unreachability Detection will
perform any needed recovery.
.
Whenever the Lifetime of an entry in the Default Router List expires,
that entry is discarded. When removing a router from the Default
Router list, the node MUST update the Destination Cache in such a way
that all entries using the router perform next-hop determination
again rather than continue sending traffic to the (deleted) router.

On the other topic...

We were also wondering why Linux does not show the REDIRECT route using userspace commands (ip monitor all, ip -6 route, route -6n). The only way (that I have found) to observe the REDIRECT route is with ip route get <IPv6Addr> or with ip -6 route show cache. I'm yet to examine the kernel sources, but a hint of how Linux might behave is described in RFC4861 Section 8.3 Host Specification. Perhaps the clue is when it states:

A host receiving a valid redirect SHOULD update its Destination Cache

So to observe the Destination Cache, I need to use one of:

ip route get <IPv6Addr>
ip -6 route show cache

Wrapping these commands so we can watch for changes, I get:

$ old=""; while :; do new=$(echo "Cache:"; ip -6 r show cache; echo "-----"; echo "Route"; ip r get 2001:2:0:1001:200:10ff:fe10:1180 2>&1; echo ======); [ "$new" != "$old" ] && date +"%F %T.%N:%n""${new}%n"; old="$new";
 sleep 1; done
2024-04-30 01:57:42.772772130:
Cache:
-----
Route
RTNETLINK answers: Network is unreachable
======

### 1. RA Prefix setup
2024-04-30 01:58:12.498733486:
Cache:
-----
Route
2001:2:0:1001:200:10ff:fe10:1180 via fe80::200:10ff:fe10:1060 dev eno0 proto ra src 2001:2:0:1000:9640:c9ff:fed6:77f6 metric 1024 hoplimit 64 pref medium
======

### 2. REDIRECT received
2024-04-30 01:58:47.548573076:
Cache:
2001:2:0:1001:200:10ff:fe10:1180 dev eno0 metric 1024 hoplimit 64 pref medium
-----
Route
2001:2:0:1001:200:10ff:fe10:1180 dev eno0 src 2001:2:0:1000:9640:c9ff:fed6:77f6 metric 1024 hoplimit 64 pref medium
======

### 3. TIMEOUT
2024-04-30 01:59:44.956057636:
Cache:
-----
Route
2001:2:0:1001:200:10ff:fe10:1180 via fe80::200:10ff:fe10:1060 dev eno0 proto ra src 2001:2:0:1000:9640:c9ff:fed6:77f6 metric 1024 hoplimit 64 pref medium
======

### 4. RA Cleanup
2024-04-30 02:00:13.583430468:
Cache:
-----
Route
RTNETLINK answers: Network is unreachable
======

[LiveFreeAndRoam]

Hi @yuwata,

I just wanted to clarify, that for the sake of conformance testing, we only need the routes with an expired prefix to be removed. For coordination, is this something you will be able to look into?

Having a mechanism to timeout static redirect routes after a period of inactivity is a nice to have, but not a concern for conformance testing.

[As an aside, To help with tracking, see the summary of current issues].

[DaanDeMeyer]

@LiveFreeAndRoam Is this one still an issue or was it fixed by one of your recent PRs?

[LiveFreeAndRoam]

This is still an issue.

[bluca]

@yuwata any update on this one?

[yuwata]

Sorry, not yet.