To enable packet forwarding need edit /etc/sysctl.conf and add or uncomment next:
net.ipv4.ip_forward=1
net.ipv6.conf.all.forwarding=1
For apply this params now, use command sysctl -p
or after reboot server this params will be applied automatically.
If used vlan-per-user often required 802.1ad standard also called as QinQ or Q-in-Q, then need to set MTU on main interface and S-VLAN, because adding to headed one more field. Interface which using QinQ usualy consist of <interface_name>.<S-VLAN>.<C-VLAN>. S-VLAN (Service VLAN) is TAG which wrap C-VLAN (Customer VLAN).
As example:
MTU
1514
| 1514
| | 1500
| | |
eth0.2001.101
| | |
| | C-VLAN
| S-VLAN
Interface
Set up MTU on interface eth0 and interface with S-VLAN
ip link set eth0 mtu 1514
ip link set eth0.2001 mtu 1514
Note:
If used bonding
need change MTU on bonding (bond0) and slaves (eth0, eth1 ...) interfaces.
If accel-ppp used as DHCP BRAS important to increase ARP cache size, otherwise you can cache overflow and clients have lost connections. Edit /etc/sysctl.conf and add next:
net.ipv4.neigh.default.gc_thresh1 = 4096
net.ipv4.neigh.default.gc_thresh2 = 8192
net.ipv4.neigh.default.gc_thresh3 = 12288
net.ipv6.neigh.default.gc_thresh1 = 4096
net.ipv6.neigh.default.gc_thresh2 = 8192
net.ipv6.neigh.default.gc_thresh3 = 12288
For apply this params now, use command sysctl -p
or after reboot server this params will be applied automatically.