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From: gaoxingwang <gaoxingwang1@huawei.com>
To: <netdev@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
	<davem@davemloft.net>, <dsahern@kernel.org>, <edumazet@google.com>,
	<kuba@kernel.org>
CC: <liaichun@huawei.com>, <yanan@huawei.com>
Subject: [Discuss]iproute2: ipv6 route add fail
Date: Fri, 5 Jan 2024 17:42:55 +0800
Message-ID: <20240105094255.1498461-1-gaoxingwang1@huawei.com>
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Hello everyone,

Here is a particular problem with routing.
Sometimes users can run the ip -6 route command to add a route whose destination address is the same as the gateway address, and it can be successfully added. However, adding another route with the same gateway address will fail later.

Example:
# ip -6 route add 2409:8080:5a0a:60c7::7/128 via 2409:8080:5a0a:60c7::7 dev eth2
# ip -6 route add 2409:8080:5a0a:60c7::8/128 via 2409:8080:5a0a:60c7::7 dev eth2
RTNETLINK answers: No route to host

Does the kernel not support this application scenario?
Or should the kernel not allow routes with the same destination address as the gateway address to be added so that other more meaningful routes can be added successfully?

This question puzzles me, thank you very much if your can reply.

Best regards,
Xingwang