After running dhclient -6 we expect the DHCPv6 assigned address to be immediately usable. That's true with the Fedora dhclient-script (and the upstream ISC DHCP one), however it's not true with the Debian dhclient-script. The Debian script can complete with the address still in "tentative" state, and the address won't be usable until Duplicate Address Detection (DAD) completes. That's arguably a bug in Debian (see link below), but for the time being we need to work around it anyway. We usually get away with this, because by the time we do anything where the address matters, DAD has completed. However, it's not robust, so we should explicitly wait for DAD to complete when we get an DHCPv6 address. Link: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1085231 Signed-off-by: David Gibson <david(a)gibson.dropbear.id.au> --- test/passt/dhcp | 2 ++ test/passt_in_ns/dhcp | 2 ++ test/pasta/dhcp | 2 ++ test/perf/passt_tcp | 2 ++ test/two_guests/basic | 3 +++ 5 files changed, 11 insertions(+) diff --git a/test/passt/dhcp b/test/passt/dhcp index e05a4bb..9925ab9 100644 --- a/test/passt/dhcp +++ b/test/passt/dhcp @@ -49,6 +49,8 @@ check [ "__SEARCH__" = "__HOST_SEARCH__" ] test DHCPv6: address guest /sbin/dhclient -6 __IFNAME__ +# Wait for DAD to complete +guest while ip -j -6 addr show tentative | jq -e '.[].addr_info'; do sleep 0.1; done gout ADDR6 ip -j -6 addr show|jq -rM '[.[] | select(.ifname == "__IFNAME__").addr_info[] | select(.prefixlen == 128).local] | .[0]' hout HOST_ADDR6 ip -j -6 addr show|jq -rM '[.[] | select(.ifname == "__HOST_IFNAME6__").addr_info[] | select(.scope == "global" and .deprecated != true).local] | .[0]' check [ "__ADDR6__" = "__HOST_ADDR6__" ] diff --git a/test/passt_in_ns/dhcp b/test/passt_in_ns/dhcp index 0ceed7c..a38a690 100644 --- a/test/passt_in_ns/dhcp +++ b/test/passt_in_ns/dhcp @@ -52,6 +52,8 @@ check [ "__SEARCH__" = "__HOST_SEARCH__" ] test DHCPv6: address guest /sbin/dhclient -6 __IFNAME__ +# Wait for DAD to complete +guest while ip -j -6 addr show tentative | jq -e '.[].addr_info'; do sleep 0.1; done gout ADDR6 ip -j -6 addr show|jq -rM '[.[] | select(.ifname == "__IFNAME__").addr_info[] | select(.prefixlen == 128).local] | .[0]' hout HOST_ADDR6 ip -j -6 addr show|jq -rM '[.[] | select(.ifname == "__HOST_IFNAME6__").addr_info[] | select(.scope == "global" and .deprecated != true).local] | .[0]' check [ "__ADDR6__" = "__HOST_ADDR6__" ] diff --git a/test/pasta/dhcp b/test/pasta/dhcp index 41556b8..d4f3ad5 100644 --- a/test/pasta/dhcp +++ b/test/pasta/dhcp @@ -35,6 +35,8 @@ check [ __MTU__ = 65520 ] test DHCPv6: address ns /sbin/dhclient -6 --no-pid __IFNAME__ +# Wait for DAD to complete +ns while ip -j -6 addr show tentative | jq -e '.[].addr_info'; do sleep 0.1; done hout HOST_IFNAME6 ip -j -6 route show|jq -rM '[.[] | select(.dst == "default").dev] | .[0]' nsout ADDR6 ip -j -6 addr show|jq -rM '[.[] | select(.ifname == "__IFNAME__").addr_info[] | select(.prefixlen == 128).local] | .[0]' hout HOST_ADDR6 ip -j -6 addr show|jq -rM '[.[] | select(.ifname == "__HOST_IFNAME6__").addr_info[] | select(.scope == "global" and .deprecated != true).local] | .[0]' diff --git a/test/perf/passt_tcp b/test/perf/passt_tcp index 089d953..5978c49 100644 --- a/test/perf/passt_tcp +++ b/test/perf/passt_tcp @@ -116,6 +116,8 @@ iperf3k ns # Reducing MTU below 1280 deconfigures IPv6, get our address back guest dhclient -6 -x guest dhclient -6 __IFNAME__ +# Wait for DAD to complete +guest while ip -j -6 addr show tentative | jq -e '.[].addr_info'; do sleep 0.1; done tl TCP RR latency over IPv4: guest to host lat - diff --git a/test/two_guests/basic b/test/two_guests/basic index ac50ff8..9ba5efe 100644 --- a/test/two_guests/basic +++ b/test/two_guests/basic @@ -40,6 +40,9 @@ guest1 while ip -j -6 addr show tentative | jq -e '.[].addr_info'; do sleep 0.1; guest2 while ip -j -6 addr show tentative | jq -e '.[].addr_info'; do sleep 0.1; done guest1 /sbin/dhclient -6 __IFNAME1__ guest2 /sbin/dhclient -6 __IFNAME2__ +# Wait for DAD to complete on the DHCP address +guest1 while ip -j -6 addr show tentative | jq -e '.[].addr_info'; do sleep 0.1; done +guest2 while ip -j -6 addr show tentative | jq -e '.[].addr_info'; do sleep 0.1; done g1out ADDR1_6 ip -j -6 addr show|jq -rM '[.[] | select(.ifname == "__IFNAME1__").addr_info[] | select(.prefixlen == 128).local] | .[0]' g2out ADDR2_6 ip -j -6 addr show|jq -rM '[.[] | select(.ifname == "__IFNAME2__").addr_info[] | select(.prefixlen == 128).local] | .[0]' hout HOST_ADDR6 ip -j -6 addr show|jq -rM '[.[] | select(.ifname == "__HOST_IFNAME6__").addr_info[] | select(.scope == "global" and .deprecated != true).local] | .[0]' -- 2.47.0