Date: Mon, 14 Jan 2019 10:21:31 -0800 (PST) From: "Rodney W. Grimes" <freebsd-rwg@pdx.rh.CN85.dnsmgr.net> To: Mark Saad <nonesuch@longcount.org> Cc: FreeBSD Hackers <freebsd-hackers@freebsd.org> Subject: Re: Removing an alias can remove routes ? Message-ID: <201901141821.x0EILVem036356@pdx.rh.CN85.dnsmgr.net> In-Reply-To: <CAMXt9NZ8VtTETH0_pRBeHZ7P%2Bgocpxa3EypWuJ6P=b8-%2B3VgqA@mail.gmail.com>
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> On Mon, Jan 14, 2019 at 11:59 AM Rodney W. Grimes > <freebsd-rwg@pdx.rh.cn85.dnsmgr.net> wrote: > > > > > All > > > I ran into a peculiar over the weekend on two FreeBSD 10-STABLE > > > servers that has me at a loss. Both servers have the same setup lacp > > > lagg wtih vlans using the lagg as a parent dev. > > > On the vlans I have some alias along with the primary ip. When a > > > alias was added or deleted routes that sourced out of the primary ip > > > on that vlan were dropped from the routing table. > > > > > > > > > So for example. I have lagg0.vlan1044 . (both servers are similarly > > > configured as routers / firewalls ) > > > > > > [root@pineapple01 ~]# ifconfig lagg0.vlan1044 > > > lagg0.vlan1044: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> > > > metric 0 mtu 1500 > > > options=300<TSO4,TSO6> > > > ether 00:0f:53:20:9b:d0 > > > inet6 fe80::20f:53ff:fe20:9bd0%lagg0.vlan1044 prefixlen 64 > > > scopeid 0x80 > > > inet 10.24.213.84 netmask 0xffffffe0 broadcast 10.24.213.95 > > > inet 10.24.212.129 netmask 0xffffffff broadcast 10.24.212.129 > > > inet 10.24.213.163 netmask 0xfffffff0 broadcast 10.24.213.175 > > > inet 10.24.213.76 netmask 0xffffffe0 broadcast 10.24.213.95 > > > inet 10.24.213.94 netmask 0xffffffe0 broadcast 10.24.213.95 > > > inet 10.24.213.89 netmask 0xffffffe0 broadcast 10.24.213.95 > > > inet 10.24.213.75 netmask 0xffffffe0 broadcast 10.24.213.95 > > > nd6 options=21<PERFORMNUD,AUTO_LINKLOCAL> > > > media: Ethernet autoselect > > > status: active > > > vlan: 1044 parent interface: lagg0 > > > > > > [root@pineapple01 ~]# netstat -nr4Wl > > > ... > > > 192.168.144.32/27 10.24.213.65 UGS 0 1500 lagg0.vlan1044 > > > 192.168.144.96/27 10.24.213.65 UGS 0 1500 lagg0.vlan1044 > > > 192.168.23.0/24 10.24.213.65 UGS 0 1500 lagg0.vlan1044 > > > 192.168.120.0/21 10.24.213.65 UGS 0 1500 lagg0.vlan1044 > > > > > > > > > So I wanted to remove the alias ended in 163 and fix its netmask back to /32 > > > > > > I ran this > > > > > > ifconfig lagg0.vlan1044 inet 10.24.213.163/24 -alias && ifconfig > > ^ delete? > > I use -alias which is an alias of -delete > > > > > > lagg0.vlan1044 inet 10.24.213.163/32 -alias This is also a delete? I am concerend that what you think the command you typed is not actually the command you typed and what you did actually type has the bad side effects. > > > and shortly there after all of the routes that went out lagg0.vlan1044 > > > were gone . I quickly undid my change and put the routes back but I am > > > not sure what caused this ? Anyone have any ideas I have done this in > > > the past with out issue and I am unsure whats changed other then the > > > box have a long up time of 463 days . > > > > I believe what happened here is that 10.24.213.163/24 when reduced > > to a network address is 10.24.213.0/24, which probably got sent to > > the route removal code, which since the route to that covers the > > gateway at 10.24.213.65 that gateway was no longer accessable > > so all routes via it got removed. > > > > ok I see what you are saying and it makes sense to me; do you know why > the routing code does not see the primary ip ( the non-alias one) is > still > live on the interface before deciding to drop the routes associated with it ? It should, but I can not see enough of your routing table to guess as to exactly what the kernel did when you removed this interface. The routes I see above all would go through the interface you showed you removed, thus they would all go away. -- Rod Grimes rgrimes@freebsd.org
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