From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by passt.top (Postfix) with ESMTP id 5EA495A026D for ; Mon, 18 Sep 2023 16:01:47 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1695045706; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=JF6uA2WNiCk/Rnb+3CBncoKd7EdWS0RYuGUvoOSHwg8=; b=TtpYnd/VO7I6ETij32VR9OpiH2TWSCY1lbUE06lajAbZKTCX2z5hZR6w7rOl7MVHiR5/1O xWip7lX2s4ZSC/3QepYe8fg7R++HVw4kYHNDYin2oRpwEyhlUvFivQZGeZKrLugqRTvQwd fbmdNIasvDfNAZc+JCUiSJ7JQQu0q2Y= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-595-0Vq2zcyVO46Du49CbuCXpQ-1; Mon, 18 Sep 2023 10:01:42 -0400 X-MC-Unique: 0Vq2zcyVO46Du49CbuCXpQ-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.rdu2.redhat.com [10.11.54.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 81145945920; Mon, 18 Sep 2023 14:01:42 +0000 (UTC) Received: from elisabeth (unknown [10.39.208.36]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 86E3B40C6EBF; Mon, 18 Sep 2023 14:01:41 +0000 (UTC) Date: Mon, 18 Sep 2023 16:01:34 +0200 From: Stefano Brivio To: Nikolay Edigaryev Subject: Re: [PATCH] arp: only send ARP replies for --gateway address Message-ID: <20230918160134.09d2b706@elisabeth> In-Reply-To: References: <20230915142045.73457-1-edigaryev@gmail.com> Organization: Red Hat MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.2 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Message-ID-Hash: BNAML5L4NW5DL2MFCGGHENIANILB4IR4 X-Message-ID-Hash: BNAML5L4NW5DL2MFCGGHENIANILB4IR4 X-MailFrom: sbrivio@redhat.com X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; emergency; loop; banned-address; member-moderation; nonmember-moderation; administrivia; implicit-dest; max-recipients; max-size; news-moderation; no-subject; digests; suspicious-header CC: David Gibson , passt-dev@passt.top X-Mailman-Version: 3.3.8 Precedence: list List-Id: Development discussion and patches for passt Archived-At: Archived-At: List-Archive: List-Archive: List-Help: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: On Mon, 18 Sep 2023 12:26:03 +1000 David Gibson wrote: > On Fri, Sep 15, 2023 at 06:20:45PM +0400, Nikolay Edigaryev wrote: > > Problem: when passt/pasta are working in a broadcast domain with more > > than one host machine, > > Oof. So, at present, passt/pasta is really not designed to have more > than a single machine on the "tap" side. Changing the ARP behaviour > is likely to be the least of the problems with that setup. Now I'm confused on which "side" this happens. :) Nikolay, can you articulate the issue a bit better? Do you really have multiple *host* machines? Does the passt process... move between them? By the way, the only concern I have with this change is that the guest might ignore the gateway address it's being assigned, for whatever reason, and by just resolving "almost everything" we guarantee the traffic goes out anyway. If there's no other way to solve the issue you're facing, I would rather propose to have this as an option, and perhaps have it off by default. -- Stefano