Hi Florian, On Mon, Aug 13, 2018 at 7:57 PM Florian Fainelli <f.faine...@gmail.com> wrote: > > On 08/13/2018 08:58 AM, Lad, Prabhakar wrote: > > Hi Andrew/Florain, > > > > On Mon, Aug 13, 2018 at 2:38 PM Andrew Lunn <and...@lunn.ch> wrote: > >> > >>>> I agree, this should be padding packets correctly, can you still > >>>> instrument cpsw to make sure that what comes to its ndo_start_xmit() is > >>>> ETH_ZLEN + tag_len or more? > >>>> > >>> Yes I can confirm the skb->len is always >= 62 (ETH_ZLEN + 2) > >> > >> Which switch are you using? > >> > >> Marvell switches use either 4 or 8 bytes of tag. Broadcom has 4, KSZ > >> has 1 for packets going to the switch, lan9303 has 4, mtd uses 4, qca > >> has 2. > >> > > I am using the KSZ switch. for Ingress it has 1 byte and for Egress it > > has 2 bytes. > > I came across patch [1] and padded 2 more bytes in ksz_xmit() and I was > > successfully able to ping from lan4 to PC. Thank you very much for > > your guidance/support. > > > > Now I have stumbled into a different issue: > > > > Case 1 Works: > > ================= > > lan0 = 192.168.0.1 > > PC1 = 192.168.0.10 > > For the above ping works from both directions. > > > > CASE 2 Doesn’t Work: > > ========================= > > lan0 = 192.168.0.1 > > PC1 = 192.168.0.10 > > lan4 = 192.168.0.4 > > PC2 = 192.168.0.11 > > > > Ping from lan0 to PC1 and PC1 to lan0 works > > But ping from PC2 to lan4 and lan4 to PC2 fails. > > > > CASE 3 Works: > > ========================= > > lan0 = 192.168.0.1 > > PC1 = 192.168.0.10 > > lan4 = 192.168.4.4 > > PC2 = 192.168.4.11 > > > > With the above setup ping works. > > > > [Query] Why does ping fail in case 2. Any thoughts what I am missing here ? > > or is it the expected behaviour ? > > For case 2, what I suspect is happening is that the machine that has > lan1/lan4, because you have put lan1/lan4 in the same subnet, does not > know how to respond to PC2 because it is unable to select an appropriate > output interface. In such cases, you might have to add an explicit /32 > route that forces telling the kernel that PC2 is accessible via lan2. > That did the trick thank you, following is my setup lan0 = 192.168.0.1 PC1 = 192.168.0.10 lan4 = 192.168.0.4 PC2 = 192.168.0.11
route add 192.168.0.11 gw 192.168.0.4 route add 192.168.0.10 gw 192.168.0.1 And now ping works either ways. Is this setup for adding the route a valid way to do it ? Or is there some standard way I need to follow which I am missing. > Andrew, do you see an other explanation for that? > > > > > [1] https://lore.kernel.org/patchwork/patch/851457/ > > This patch works, but I think it is still working by "accident" in that > if you have both VLAN tags + KSZ tag, you would likely still be too > short by a few bytes. > too take care of this now I making sure the skb->len is padded to VLAN_ETH_ZLEN in tag_ksz.c ksz_xmit() function. Cheers, --Prabhakar Lad
