On 8/16/17 4:37 PM, David Ahern wrote: > One nagging difference between ipv4 and ipv6 is host routes for ipv6 > addresses are installed using the loopback device or VRF / L3 Master > device. e.g., > > 2001:db8:1::/120 dev veth0 proto kernel metric 256 pref medium > local 2001:db8:1::1 dev lo table local proto kernel metric 0 pref medium > > Using the loopback device is convenient -- necessary for local tx, but > has some nasty side effects, most notably setting the 'lo' device down > causes all host routes for all local IPv6 address to be removed from the > FIB and completely breaks IPv6 networking across all interfaces. > > This patch puts FIB entries for IPv6 routes against the device. This > simplifies the routes in the FIB, for example by making dst->dev and > rt6i_idev->dev the same (a future patch can look at removing the device > reference taken for rt6i_idev for FIB entries). For example: > > $ ip -6 r ls table all | grep veth1 > 2001:db8:99::/120 dev veth1 proto kernel metric 256 pref medium > anycast 2001:db8:99:: dev veth1 table local proto kernel metric 0 pref > medium > local 2001:db8:99::1 dev veth1 table local proto kernel metric 0 pref > medium > > When copies are made on FIB lookups, the cloned route has dst->dev > set to loopback (or the L3 master device). This is needed for the > local Tx of packets to local addresses. > > With fib entries allocated against the real network device, the addrconf > code that reinserts host routes on admin up of 'lo' is no longer needed. > > Signed-off-by: David Ahern <dsah...@gmail.com> > --- > net/ipv6/addrconf.c | 42 ------------------------------------------ > net/ipv6/route.c | 46 ++++++++++++++++++++++++++++++++++------------ > 2 files changed, 34 insertions(+), 54 deletions(-) >
DaveM: please drop this one. I found a use case that is failing: UDP packets to a local linklocal address with no server are not getting the ICMP unreachable. Will send a v2 when tests complete.
