# CARP interface is unreachable.



## blitzkrieg (Jul 19, 2012)

I want to make fault-tolerant gateway and trying to test CARP interface.


```
cat /usr/src/sys/i386/conf/MYKERN |grep carp
device          carp
```


```
uname -a
FreeBSD ClusterN2 9.0-RELEASE FreeBSD 9.0-RELEASE #1: Fri Jul 13 17:08:32 MSK 2012     root@ClusterN1:/usr/obj/usr/src/sys/MYKERN  i386
```


```
cat /etc/rc.conf |grep -v '#'
hostname="ClusterN1"
ifconfig_em0="inet 172.16.6.246 netmask 255.255.0.0"
defaultrouter="172.16.5.2"
sshd_enable="YES"
dumpdev="AUTO"
cloned_interfaces="carp0"
ifconfig_carp0=" vhid 1 pass 123456 172.16.6.245/16 "

firewall_enable="YES"
firewall_script="/etc/ipfw.conf"
```


```
cat /etc/rc.conf | grep -v '#'
hostname="ClusterN2"
ifconfig_em0="inet 172.16.6.247 netmask 255.255.0.0"
defaultrouter="172.16.5.2"
sshd_enable="YES"
dumpdev="AUTO"
cloned_interfaces="carp0"
ifconfig_carp0="vhid 1 advskew 100 pass 123456 172.16.6.245/16"

firewall_enable="YES"
firewall_script="/etc/ipfw.conf"
```


```
ifconfig carp0
carp0: flags=49<UP,LOOPBACK,RUNNING> metric 0 mtu 1500
        inet 172.16.6.245 netmask 0xffff0000
        nd6 options=29<PERFORMNUD,IFDISABLED,AUTO_LINKLOCAL>
        carp: MASTER vhid 1 advbase 1 advskew 0
```


```
ifconfig carp0
carp0: flags=49<UP,LOOPBACK,RUNNING> metric 0 mtu 1500
        inet 172.16.6.245 netmask 0xffff0000
        nd6 options=29<PERFORMNUD,IFDISABLED,AUTO_LINKLOCAL>
        carp: BACKUP vhid 1 advbase 1 advskew 100
```

172.16.6.246 and 172.16.6.247 is virtual hosts on VMWare VSphere. 172.16.6.246 and 172.16.6.247 pinging with no losen packet and low latency. 172.16.6.246 is a copy of 172.16.6.246 with different address, hostname, MAC. Kernel and World is the same.

If I turn off MASTER BACKUP become MASTER. But pinging of 172.16.6.245 from my address 172.16.6.242 failed. What am I doing wrong?


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## glocke (Aug 21, 2012)

Hi, 

probably ESX is blocking, for me it helped to set Net.ReversePathFwdCheckPromisc to 1 in every involved ESX. You may also need to enable Promiscuous Mode for that vSwitch. See http://doc.pfsense.org/index.php/CARP_Configuration_Troubleshooting.

hth glocke


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