Re: bin/44032: pppd: proxyarp is not working

[Egervary Gergely <gergely%egervary.hu@localhost>]

The following reply was made to PR bin/44032; it has been noted by GNATS.

From: Egervary Gergely <gergely%egervary.hu@localhost>
To: Christos Zoulas <christos%zoulas.com@localhost>
Cc: gnats-bugs%NetBSD.org@localhost, gnats-admin%netbsd.org@localhost, 
 netbsd-bugs%netbsd.org@localhost
Subject: Re: bin/44032: pppd: proxyarp is not working
Date: Tue, 04 Dec 2012 21:50:25 +0100

 > | A year has passed, and it seems we still do not have proxyarp working
 > | properly.
 > |
 > | I'm now running on todays 5.1_STABLE.
 > |
 > | [10.0.0.192]---ppp---[10.0.0.1]---ethernet---[10.0.0.2]
 > |
 > | - pppd on 10.0.0.1 says:
 > |    pppd[1291]: found interface vlan10 for proxy arp
 > |    (looks okay)
 > |    
 > | - 10.0.0.192 can ping 10.0.0.1, but not 10.0.0.2 and vice versa
 > |
 > | - on 10.0.0.1:
 > |    # arp 10.0.0.192
 > |    arp: 10.0.0.192 (10.0.0.192) -- no entry
 > |
 > |    # arp -s 10.0.0.192 00:11:22:33:44:55 pub
 > |    arp: set: proxy entry exists for non 802 device
 > |
 > | - on 10.0.0.2:
 > |    # arp 10.0.0.192
 > |    arp: 10.0.0.192 (10.0.0.192) -- no entry
 > |
 > |    # tcpdump -i vlan10
 > |    00:17:47.028819 ARP, Request who-has 10.0.0.192 tell 10.0.0.2,
 > |    length 28
 > |    00:17:48.036521 ARP, Request who-has 10.0.0.192 tell 10.0.0.2,
 > |    length 28
 > |    ...
 > |
 > | Any ideas?
 >
 > Can you put some debugging in sifproxyarp and see what's going on?
 
 Finally, I have done some debugging.
 
 - In sifproxyarp(), arpmsg.hwa contains the correct MAC address.
 - Socket write() succeeds with 112 bytes written, that looks good.
 - If I comment out the socket write(), and manually enter the
 arp entry (arp -s 10.0.0.192 <mac> pub proxy) then the kernel still
 does not respond to arp who-has requests.
 
 Now, some questions:
 
 - The proxy arp entries are not visible in `arp -a'. Should not they
 be visible? For example, on Linux they are visible.
 
 - Once I add an arp entry with `arp -s 10.0.0.192 <mac> pub proxy'
 I cannot remove it later. (arp: delete: can't locate 10.0.0.192)
 Is this normal?
 
 - Is proxy arp working good for somebody out there? Could you please
 test it?
 
 Thank you.
 -- 
 Gergely EGERVARY