I am going on week 2 and still unable to get this to work.
I am running Squid Cache: Version 3.5.20 on Linux Oracle Enterprise Server 7.7 (3.10.0-1062.9.1.0.1.el7.x86_64).
I try to create the gre0 interface in /etc/sysconfig/network-script/ifcfg-gre0 with the following:
/etc/sysconfig/network-scripts/ifcfg-gre0
DEVICE=gre0
BOOTPROTO=static
IPADDR=<random ip address, 10.10.10.1>
NETMASK=255.255.255.252
ONBOOT=yes
IPV6INIT=no
Then using iptables rule
iptables -t nat -A PREROUTING -i gre0 -p tcp -m tcp --dport 80 -j DNAT --to <ip address of proxy server>:3128
When I try to restart networking I am getting this error message:
-- Unit network.service has begun starting up.
Jan 14 14:07:27 PROXY_SERVER_NAME network[6331]: Bringing up loopback interface: [ OK ]
Jan 14 14:07:27 PROXY_SERVER_NAME kernel: RTL8211E Gigabit Ethernet r8169-200:00: attached PHY driver [RTL8211E Gigabit Ethernet] (mii_bus:phy_addr=r8169-200
Jan 14 14:07:28 PROXY_SERVER_NAME kernel: IPv6: ADDRCONF(NETDEV_UP): p1p1: link is not ready
Jan 14 14:07:29 PROXY_SERVER_NAME kernel: libphy: r8169-200:00 - Link is Up - 100/Full
Jan 14 14:07:29 PROXY_SERVER_NAME kernel: IPv6: ADDRCONF(NETDEV_CHANGE): p1p1: link becomes ready
Jan 14 14:07:32 PROXY_SERVER_NAME network[6331]: Bringing up interface p1p1: [ OK ]
Jan 14 14:07:32 PROXY_SERVER_NAME network[6331]: Bringing up interface p1p1_20200114: RTNETLINK answers: File exists
Jan 14 14:07:32 PROXY_SERVER_NAME network[6331]: [ OK ]
Jan 14 14:07:32 PROXY_SERVER_NAME network[6331]: Bringing up interface gre0: ERROR : [/etc/sysconfig/network-scripts/ifup-tunnel] Device 'gre0' isn't su
Jan 14 14:07:32 PROXY_SERVER_NAME /etc/sysconfig/network-scripts/ifup-tunnel[6607]: Device 'gre0' isn't supported as a valid GRE device name.
Jan 14 14:07:32 PROXY_SERVER_NAME network[6331]: [FAILED]
Jan 14 14:07:32 PROXY_SERVER_NAME systemd[1]: network.service: control process exited, code=exited status=1
Jan 14 14:07:32 PROXY_SERVER_NAME systemd[1]: Failed to start LSB: Bring up/down networking.
-- Subject: Unit network.service has failed
-- Defined-By: systemd
-- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel
--
-- Unit network.service has failed.
I have looked for a decent guide on setting up a WCCP proxy server with squid but most I have seen are for older versions, CentOS 6.5 for example, or for setting up a tunnel between two Linux servers. It all sounds so easy but yet i have yet to get anything to work. Any suggestions or guidance is greatly appreciated as I am at a loss and just continue to feel like I am going in circles.
Anyone setup an Oracle Linux 7 / CentOS 7 WCCP proxy server in transparent mode, think that is what it is called where no configuration is required on the endpoints browsers?