FREEBSD 使用 ng_eiface 和 ng_bridge 创建虚拟以太网接口

使用通用以太网接口 netgraph 节点，可以创建可通过 ifconfig(8) 访问的新接口，使用以太网桥接 netgraph 节点类型可以在不同的以太网节点类型之间进行桥接。通过组合这两种类型，可以在同一物理接口上创建具有不同以太网 (MAC) 地址的多个接口。这是从标准 FreeBSD 发行版附带的 netgraph ether.bridge 示例脚本修改而来的示例脚本：

 1 #!/bin/sh
 2 #
 3 # Author: Jan Melen-jan(at)melen.org
 4 #
 5 # This script sets up an Ethernet bridging network across multiple
 6 # ng_eiface(4) using the ng_bridge(4) and ng_ether(4) netgraph
 7 # node types.
 8 #
 9 
10 BRIDGE_NAME="bnet0"
11 
12 VIRTUAL_IFACES="ngeth0 ngeth1 ngeth2"
13 LOCAL_IFACE="bge0"
14 
15 # Routine to verify node's existence.
16 vether_verify() {
17     ngctl info ${BRIDGE_NAME}: >/dev/null 2>&1
18     if [ $? -ne 0 ]; then
19         echo "${BRIDGE_NAME}: bridge network not found"
20         exit 1
21     fi
22 }
23 
24 # Start/restart routine.
25 vether_start() {
26 
27     # Load netgraph KLD's as necessary.
28     for KLD in ng_ether ng_bridge; do
29         if ! kldstat -v | grep -qw ${KLD}; then
30             echo -n "Loading ${KLD}.ko... "
31             kldload ${KLD} || exit 1
32             echo "done"
33         fi
34     done
35 
36     # Reset all interfaces.
37     vether_stop
38 
39     # Verify all interfaces exist.
40     LINKNUM=2
41    ETHERADDR=`ifconfig ${LOCAL_IFACE} ether | grep "ether" | cut -b 8-22`
42     for ETHER in ${VIRTUAL_IFACES}; do
43         if ! ngctl info ${ETHER}: >/dev/null 2>&1; then
44            ngctl mkpeer . eiface hook ether
45         fi
46        ifconfig ${ETHER} ether ${ETHERADDR}${LINKNUM}
47         ifconfig ${ETHER} up || exit 1
48         LINKNUM=`expr ${LINKNUM} + 1`
49     done
50 
51     # Create new ng_bridge(4) node, attached to the first interface.
52     ngctl mkpeer ${LOCAL_IFACE}: bridge lower link0 || exit 1
53     ngctl name ${LOCAL_IFACE}:lower ${BRIDGE_NAME} || exit 1
54    ngctl connect ${LOCAL_IFACE}: ${BRIDGE_NAME}: upper link1 || exit 1
55 
56     LINKNUM=2
57     # Attach other interfaces as well.
58     for ETHER in ${VIRTUAL_IFACES}; do
59         if [ ${LINKNUM} != 0 ]; then
60             ngctl connect ${ETHER}: ${BRIDGE_NAME}: \
61                 ether link${LINKNUM} || exit 1
62         fi
63         LINKNUM=`expr ${LINKNUM} + 1`
64     done
65 
66     # Set all interfaces in promiscuous mode and don't overwrite src addr.
67     for ETHER in ${LOCAL_IFACE}; do
68         ngctl msg ${ETHER}: setpromisc 1
69         ngctl msg ${ETHER}: setautosrc 0
70     done
71 }
72 
73 # Stop routine.
74 vether_stop() {
75     ngctl kill ${BRIDGE_NAME}: >/dev/null 2>&1
76     for ETHER in ${VIRTUAL_IFACES} ${LOCAL_IFACE}; do
77         ngctl kill ${ETHER}: >/dev/null 2>&1
78     done
79 }
80 
81 # Main entry point.
82 case $1 in
83     start)
84         vether_start
85         ;;
86     stop)
87         vether_verify
88         vether_stop
89         ;;
90     *)
91         echo "usage: $0 [ start | stop ]"
92         exit 1
93 esac

标签：bridge,LINKNUM,ngctl,以太网,exit,ether,ng,ETHER
来源： https://www.cnblogs.com/ip99/p/15264942.html