[FS#154] fw: can not ping the router via link local on all nodes multicast 'ping6 ff02:1%eth0'

[LEDE Bugs]

The following task has a new comment added:

FS#154 - fw: can not ping the router via link local on all nodes multicast 'ping6 ff02:1%eth0'
User who did this - Github Issues (github-import)

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**DPini commented on Jun 22
**
I am able to reproduce this bug.
I have been looking into it, and I have found that deleting this rule

ip6tables -t filter -D OUTPUT -m id --id 0x66773300 -m conntrack --ctstate INVALID -j DROP 

from the ip6tables firewall allows to ping it with it's IPv6 Link-local address

Comparing the output of fw3 -6 print (LEDE trunk) with a router running OpenWRT Breaking Barrier, this rule doesn't appear.

Attached you can find the outputs of fw3

[[https://github.com/lede-project/source/files/327561/lede_fw3_6_print.txt|lede_fw3_6_print.txt]]\\
[[https://github.com/lede-project/source/files/327562/openwrt_BB_fw3_6_print.txt|openwrt_BB_fw3_6_print.txt]]

**jow- commented on Jul 22
**
You should be able to inhibit the drop rule by using option drop_invalid 0 in the defaults section.

**lynxis commented 26 days ago
**
@jow- any idea how we can fix this with option drop_invalid 1?
Is this is kernel bug, that the kernel does not track the state of icmp6 mcast replies correct?

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More information can be found at the following URL:
https://bugs.lede-project.org/index.php?do=details&task_id=154#comment367