Re: ping -6 ignores -e parameter

Hello, Alan!

I'm sorry, I'm forget to add freebsd-stable@ to CC: list.

Yes, I'm using FreeBSD 13:
13.0-STABLE

Today I have a native IPv6 access and my inet6 routing table is:
# netstat -rn6 | grep -v -e lo0
Routing tables

Internet6:
Destination                       Gateway                       Flags 
   Netif Expire
default                           fe80::206:29ff:fee9:32a9%lan0 UG 
    lan0
fd00:dead:beef:100::/64           link#5                        U 
    lan0
fe80::%lan0/64                    link#5                        U 
    lan0
fe80::%bridge0/64                 link#6                        U 
bridge0

This means my default gateway is reachable via lan0.
A node which link-local address fe80::2a0:98ff:fe1d:e270 is reachable 
via bridge0:
# ping -c 1 fe80::2a0:98ff:fe1d:e270%bridge0
PING6(56=40+8+8 bytes) fe80::5a9c:fcff:fe10:ff9e%bridge0 --> 
fe80::2a0:98ff:fe1d:e270%bridge0
16 bytes from fe80::2a0:98ff:fe1d:e270%bridge0, icmp_seq=0 hlim=64 
time=0.804 ms

But ping anyway sends packets via lan0.
Also I tried to configure fd13:dead:beef::2 on bridge0, on corresponding 
node I configured fd13:dead:beef::1, and then run a command:
ping -6 -e fd13:dead:beef::1 google.com

In this way ping uses source IP address from bridge0 interface, but 
sends via lan0 and to next-hop fe80::206:29ff:fee9:32a9%lan0:
# tcpdump -epni lan0 icmp6
12:33:23.308763 8c:ec:4b:e9:28:23 > 00:06:29:e9:32:a9, ethertype IPv6 
(0x86dd), length 70: fd13:dead:beef::2 > 2a00:1450:4010:c1e::8a: ICMP6, 
echo request, seq 52, length 16

I'm wrote a simple script to check this problem. I checked this script 
on image of VM from freebsd'site which FreeBSD-13.
Please see attached file.

On 15/12/2021 21:32, Alan Somers wrote:
> On Wed, Dec 15, 2021 at 11:16 AM KOT MATPOCKuH <matpockuh@gmail.com> wrote:
>>
>> Hello!
>>
>> In a man page for ping(8) and in it's help output I found option "-e":
>>       -e gateway
>>               Specifies to use gateway as the next hop to the destination.  The
>>               gateway must be a neighbor of the sending node.
>>
>> I tried to use this argument, ping ignores this parameter and sends the packet via default gateway.
>> For example I have a tun0 which has ipv6 default gw, and an established bridge0 which has available some LL addresses:
>> Neighbor                             Linklayer Address  Netif Expire    S Flags
>> fe80::2a0:98ff:fe1d:e270%bridge0     00:a0:98:1d:e2:70 bridge0 23h56m34s S R
>>
>> I tried to run:
>> ping -6 -e FE80::2A0:98FF:FE1D:E270%bridge0 google.com
>> But the packet was sent via tun0 interface.
>>
>> What is wrong with it?
>>
>> --
>> MATPOCKuH
> 
> What version of FreeBSD are you using?  There was a major change to
> ping's code in FreeBSD 13.  Please show the output of
> 'freebsd-version' and 'netstat -rn'.
> -Alan
>