iprout2, одновременное использование двух интернет каналов

IF1=wwan0
IF2=wwan1

IP1="`ip addr show $IF1 | grep 'inet ' | awk '{print $2}' | sed 's/'[/]..'//'`"
echo "IP1:$IP1"
IP2="`ip addr show $IF2 | grep 'inet ' | awk '{print $2}' | sed 's/'[/]..'//'`"
echo "IP2:$IP2"

P1="`ip addr show $IF1 | grep 'inet ' | awk '{print $4}'`"
echo "P1:$P1"
P2="`ip addr show $IF2 | grep 'inet ' | awk '{print $4}'`"
echo "P2:$P2"

P1_NET="`ifconfig $IF1 | grep 'inet ' | awk '{print $4}' | sed 's/'Mask:'//'`"
echo "P1_NET:$P1_NET"
P2_NET="`ifconfig $IF2 | grep 'inet ' | awk '{print $4}' | sed 's/'Mask:'//'`"
echo "P2_NET:$P2_NET"

echo "echo: ip route add $P1_NET dev $IF1 src $IP1 table T1"
ip route add $P1_NET dev $IF1 src $IP1 table T1
echo "echo: ip route add default via $P1 table T1"
ip route add default via $P1 table T1
echo "echo: ip route add $P2_NET dev $IF2 src $IP2 table T2"
ip route add $P2_NET dev $IF2 src $IP2 table T2
echo "echo: ip route add default via $P2 table T2"
ip route add default via $P2 table T2

echo "echo: ip route add $P1_NET dev $IF1 src $IP1"
ip route add $P1_NET dev $IF1 src $IP1
echo "echo: ip route add $P2_NET dev $IF2 src $IP2"
ip route add $P2_NET dev $IF2 src $IP2

echo "echo: ip route add default via $P1"
ip route add default via $P1

echo "echo: ip rule add from $IP1 table T1"
ip rule add from $IP1 table T1
echo "echo: ip rule add from $IP2 table T2"
ip rule add from $IP2 table T2

echo "echo: ip route add default scope..."
ip route add default scope global nexthop via $P1 dev $IF1 weight 1 \
nexthop via $P2 dev $IF2 weight 1

IP1:10.237.120.238
IP2:10.209.9.208
P1:10.237.120.239
P2:10.209.9.223
P1_NET:255.255.255.248
P2_NET:255.255.255.224
echo: ip route add 255.255.255.248 dev wwan0 src 10.237.120.238 table T1
echo: ip route add default via 10.237.120.239 table T1
RTNETLINK answers: Invalid argument
echo: ip route add 255.255.255.224 dev wwan1 src 10.209.9.208 table T2
echo: ip route add default via 10.209.9.223 table T2
RTNETLINK answers: Invalid argument
echo: ip route add 255.255.255.248 dev wwan0 src 10.237.120.238
echo: ip route add 255.255.255.224 dev wwan1 src 10.209.9.208
echo: ip route add default via 10.237.120.239
RTNETLINK answers: Invalid argument
echo: ip rule add from 10.237.120.238 table T1
echo: ip rule add from 10.209.9.208 table T2
echo: ip route add default scope...
RTNETLINK answers: Invalid argument

cat /etc/iproute2/rt_tables
#
# reserved values
#
255     local
254     main
253     default
0       unspec
#
# local
#
#1      inr.ruhep
1 T1
2 T2