[draft] [v3.29] fix for issues on ipv6 enabled clusters #834
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Signed-off-by: Aritra Basu <[email protected]>
Signed-off-by: Aritra Basu <[email protected]>
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Signed-off-by: Aritra Basu <[email protected]>
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Signed-off-by: Aritra Basu <[email protected]>
Signed-off-by: Aritra Basu <[email protected]>
This patch removes the nodeIP from the tap0 interface in VPP.
With this patch, for each uplink interface eth0 with IP 192.168.0.1/24
we create a corresponding tap0 set up the following way:
* In VRF:0
* we create the af_packet interface with IP 192.168.0.1/24
* we receive 192.168.0.1/32 locally, traffic to 192.168.0.1 without listeners
will end up in punt
* In the punt table
* we route 192.168.0.1/24 via tap0 192.168.0.1
* In linux
* tap0 has the 192.168.0.1/24 address
* tap0 will respond to ARPs as VPP has arp proxy enabled
* In a host-tap-eth0-v4 VRF
* we place the tap0 interface
* we give it the 169.254.0.1/32 address, overridable with CALICOVPP_TAP0_ADDR
* we enable IP6 without setting an address
* we add a static neighbor for 192.168.0.1 to the MAC of the linux side of the tap
* If we specify a rule in redirectToHostRules (e.g. for DNS in kind)
* we will have the classifier entry redirect to tap0 192.168.0.1
Signed-off-by: Nathan Skrzypczak <[email protected]>
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IPv6 gateway traffic (DHCPv6/ICMP) fails when VPP takes over the uplink. - Without gateway ND proxy, host NS for the default gateway is dropped by VPP with "neighbor solicitations for unknown targets" error due to missing /128 target entry in the tap FIB. Fix: - Enable ND proxy for the gateway on the tap so the host can resolve the gateway via VPP. Signed-off-by: Aritra Basu <[email protected]>
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January 24, 2026 18:55
Configure ip6tables mangle rule to set hop limit to 2 for DHCPv6 OUTPUT traffic from client (sport 546) to server (dport 547). This prevents VPP from dropping DHCPv6 SOLICIT/REQUEST packets when it decrements hop-limit by 1 during forwarding. Since clients generate SOLICIT/REQUEST with hop-limit=1, without this rule VPP drops the packet (ip6 ttl <= 1) with ICMP time exceeded, causing DHCPv6 lease negotiation to fail. The rule is checked for existence before adding to prevent duplicates since ip6tables does not auto-dedupe rules. The rule is also cleaned up during configuration restoration. Signed-off-by: Aritra Basu <[email protected]>
Link-local addresses are not routable. When synchronizing Linux routes to VPP's uplink interface, filter out link-local addresses so that they are not added to VPP's main VRF routing table. Signed-off-by: Aritra Basu <[email protected]>
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Capture ID_NET_NAME_* properties before VPP driver unbind and restore them via udev rules after VPP creates host-facing tap/tun interface. This is needed for IAID generation by DHCPv6 client in systemd-networkd to be consistent across VPP lifecycle on the node. Key changes: - Add new CAPTURE_HOST_UDEV_PROPS hook that runs before PreconfigureLinux() - Store ID_NET_NAME_* values and MAC address while interface still has original driver - Create udev rules for the interface to restore ID_NET_NAME_* values after VPP runs - Cleanup udev rules on VPP shutdown - CAPTURE_HOST_UDEV_PROPS → capture, VPP_DONE_OK/ERRORED → cleanup Signed-off-by: Aritra Basu <[email protected]>
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[WIP] cherry-pick of fixes from
masterfor issues on ipv6 enabled clusters