VPP/Pure L3 Between Namespaces with /32s

Method 1

Setup

INDECES=(1 2)
LOOP_INT=$(sudo vppctl create loopback interface)
LOOP_IDX=$(sudo vppctl show int | grep ${LOOP_INT} | awk '{print $2}')
sudo vppctl set interface ip address ${LOOP_INT} 10.10.1.1/24
sudo vppctl set int state ${LOOP_INT} up
sudo vppctl set ip arp proxy 10.10.1.2-10.10.1.255
for i in ${INDECES[@]}
do
    INDEX=${i};HNAME=host${INDEX};IP=10.10.1.$((${INDEX}+1));IPGW=10.10.1.1
    #Create namespace
    sudo ip netns add ${HNAME}

    # Create link and add it to namespace
    sudo ip link add name vpp2${HNAME} type veth peer name ${HNAME}
    sudo ip link set ${HNAME} netns ${HNAME}
    sudo ip link
    sudo ip netns exec ${HNAME} ip link

    # Turn up link in namespace
    sudo ip netns exec ${HNAME} ip link set dev ${HNAME} up

    # Bring up link in root ns
    sudo ip link set dev vpp2${HNAME} up

    # Fire up a tcpdump on interface in namespace
    sudo ip netns exec ${HNAME} tcpdump -i ${HNAME} -w /tmp/tcpdump-${HNAME}.libpcap &

    # Configure IP address on interface in namspace
    sudo ip netns exec ${HNAME} ip addr add ${IP}/24 dev ${HNAME}
    sudo ip netns exec ${HNAME} ip addr show ${HNAME}

    # Create host interface in vpp attached to other end of veth pair
    sudo vppctl create host-interface name vpp2${HNAME}
    sudo vppctl show hardware

    # Set up as unumbered interface against LOOP_INT
    INT_IDX=$(sudo vppctl show int | grep host-vpp2${HNAME} | awk '{print $2}')
    echo ${INT_IDX}
    echo sw_interface_set_unnumbered sw_if_index ${LOOP_IDX} unnum_if_index ${INT_IDX} | sudo vpp_api_test | grep -v "#vat"

    # Setup arp proxy
    sudo vppctl set interface proxy-arp host-vpp2${HNAME} enable

    # Configure route in vpp to namespace /32
    sudo vppctl ip route add ${IP}/32 via ${IP} host-vpp2${HNAME}
    sudo vppctl show ip fib ${IP}/32

    # Turn vpp side interfaces up
    sudo vppctl set int state host-vpp2${HNAME} up

    # Turn on trace
    sudo vppctl trace add af-packet-input 100

    # Configure default route in namespace to GW
    sudo ip netns exec ${HNAME} ip route add default via ${IPGW} dev ${HNAME}
    sudo ip netns exec ${HNAME} ip route
done

Method 2

Setup

INDECES=(1 2)
for i in ${INDECES[@]}
do
    INDEX=${i};HNAME=host${INDEX};IP=10.10.1.$((${INDEX}+1));IPGW=10.10.1.1
    #Create namespace
    sudo ip netns add ${HNAME}

    # Create link and add it to namespace
    sudo ip link add name vpp2${HNAME} type veth peer name ${HNAME}
    sudo ip link set ${HNAME} netns ${HNAME}
    sudo ip link
    sudo ip netns exec ${HNAME} ip link
    
    # Capture Namespace Mac address
    MACADDR=$(sudo ip netns exec ${HNAME} ip link show dev ${HNAME} | grep link | awk '{print $2}')
    echo "MACADDR: ${MACADDR}"

    # Turn up link in namespace
    sudo ip netns exec ${HNAME} ip link set dev ${HNAME} up

    # Bring up link in root ns
    sudo ip link set dev vpp2${HNAME} up

    # Fire up a tcpdump on interface in namespace
    sudo ip netns exec ${HNAME} tcpdump -i ${HNAME} -w /tmp/tcpdump-${HNAME}.libpcap &

    # Configure IP address on interface in namspace
    sudo ip netns exec ${HNAME} ip addr add ${IP}/32 dev ${HNAME}
    sudo ip netns exec ${HNAME} ip addr show ${HNAME}

    # Create host interface in vpp attached to other end of veth pair
    sudo vppctl create host-interface name vpp2${HNAME}
    sudo vppctl show hardware

    # Turn on trace
    sudo vppctl trace add af-packet-input 100

    # Configure route in vpp to namespace /32
    sudo vppctl ip route add ${IP}/32 via ${IP} host-vpp2${HNAME}
    sudo vppctl show ip fib ${IP}/32

    # Assign 127.0.0.* IP to vpp interface.  This is done to force interface into IP mode
    sudo vppctl set interface ip address host-vpp2${HNAME} 127.0.0.$((${INDEX}+1))/32
    sudo vppctl set ip arp host-vpp2${HNAME} ${IP} ${MACADDR}
    sudo vppctl set int state host-vpp2${HNAME} up

    # Capture VPP side mac address
    VPP_MACADDRESS=$(sudo vppctl show hardware host-vpp2${HNAME} | grep "Ethernet address" | awk '{print $3}')

    # Staticly peg up arp entry for vpp side of interface associated to GW address
    sudo ip netns exec ${HNAME} ip neigh add ${IPGW} lladdr ${VPP_MACADDRESS} dev ${HNAME}

    # Configure route to GW IP in namespace
    sudo ip netns exec ${HNAME} ip route add ${IPGW} dev ${HNAME} scope link

    # Configure default route in namespace to GW
    sudo ip netns exec ${HNAME} ip route add default via ${IPGW} dev ${HNAME}
    sudo ip netns exec ${HNAME} ip route
done

Verify

for i in ${INDECES[@]}
do
    INDEX=${i};HNAME=host${INDEX};IP=10.10.1.$((${INDEX}+1));IPGW=10.10.1.1
    for j in ${INDECES[@]}
    do
        PINGIP=10.10.1.$((${j}+1))
        PINGHNAME=host${j}
        if [ ${PINGIP} != ${IP}  ]; then
           echo "Pinging from ${HNAME} to ${PINGHNAME} "
           sudo ip netns exec ${HNAME} ping -c 2 10.10.1.$((${j}+1))
        fi
    done
done
sudo vppctl show trace
for i in ${INDECES[@]}
do
    INDEX=${i};HNAME=host${INDEX};IP=10.10.1.$((${INDEX}+1));IPGW=10.10.1.1
    sudo tcpdump -r /tmp/tcpdump-${HNAME}.libpcap -e
done

Cleanup

INDECES=(1 2)
for i in ${INDECES[@]}
do
   INDEX=${i};HNAME=host${INDEX};IP=10.10.1.$((${INDEX}+1));IPGW=10.10.1.1
   sudo ip netns del ${HNAME}
   sudo ip link del vpp2${HNAME}
   ps -ef | grep /tmp/tcpdump-${HNAME}.libpcap | awk '{print $2}' | xargs sudo kill
done
sudo service vpp restart