For those of you who are still using IPv6, you may be wondering how to disable IPv6 on your router. The good news is that it’s actually quite simple to do so. In fact, there are many ways to do it, including through your router’s network settings and even through Terminal commands. There are even workarounds available for those who are concerned about security and want to avoid IPv6 altogether.
ICMPv6 type 135 Neighbor Solicitation (NS) packet
An ICMPv6 type 135 Neneigbor Solicitation (NS) message is a non-intrusive method of locating an IPv6 address. It is an efficient alternative to broadcasting ARP requests, and it can be used to determine a neighbor’s physical address. Routers send these messages periodically to discover other devices on their network.
The NS message is similar to the ARP request message in IPv4. The NS message is destined to a multicast address. Only a node with the same last 24 bits as the destination can receive it. This reduces the chances of broadcast storms. The NA message is actively sent when the link layer address of a node changes.
The ND protocol is an extension of the ICMPv6 protocol. It is a protocol that uses ICMPv6 messages to acquire a neighbor’s link-layer address and verify its reachability. It also informs neighboring nodes of changes to the link layer, advertises flag bits, and solicits an address prefix. In addition, ND uses ICMPv6 to report errors and perform information-related tasks.
Configuring LAN ports
Firstly, you should configure the IPv6 setting on your router. In the router, you can do this by changing the default settings in System > Network. Usually, this feature is disabled by default. Nevertheless, you can enable it by using the command “ipv6 enable”. This command will also allow you to change the IPv6 setting on individual LAN ports. This method is not recommended for new routers.
Related: How to Disable IPv6 on your PC
Next, navigate to the advanced settings of your router. There, select the LAN tab. Click on the IPv6 radio button. Uncheck the boxes next to Use Rapid Commit Option and Send Hints for the Renewal of Previous IP at Startup. You also need to enable Only Request Stateless Information. This will cause the interface to operate in stateless mode, which means that it will only request network parameters and not stateful ones. In the Advanced tab, check Enable Listening to Router Advertisement.
Suppressing RAs with IPv6 on router is a way to deploy IPv6 selectively. This configuration command tells the router to only respond to RSs instead of multicast packets. The default SLAAC settings are incompatible with IPv6 and this command is necessary. However, there are several other configuration commands available that do the same thing.
To suppress IPv6 RAs, you must first enable a configuration option. For example, the managed-config flag will allow you to configure a DHCP address. If you do not enable this configuration, your router will advertise the DHCP address by default. You should also set the reachable-time field to zero to enable RA-protected IPv6 connections.
Alternatively, you can enable ipv6-only mode. If enabled, a default route with a valid lifetime of 30 seconds will be used. In contrast, an inet6 address with a preferred-lft of 40 seconds will be used. Using a DNS server that supports IPv6 will prevent the router from being flooded with RA-spoofed traffic.
Disabling IPv6 in your router can be done easily by configuring it to use a different network prefix. Using a DHCPv6 server will allow you to specify up to three IPv6 addresses, one for each VLAN. You can specify the domain name of the DHCPv6 server, as well as the encoding method and client FQDN option.
IPv6 uses a stateful DHCPv6 server to assign addresses to hosts. It keeps track of each assignment, logs it, and determines its expiration time. However, unlike IPv4, DHCPv6 does not provide a default gateway address. Only routers that send Router Advertisement messages will receive a dynamic gateway address. The good news is that there are several ways to configure your router to provide IPv6 addresses to your users.
The DHCPv6 server is typically on a separate link/subnet from most of its clients. A router on a link has to be configured as a relay agent (RA) to communicate DHCPv6 addresses to clients. This router can be a computer or another router that is configured as a low-priority server. This way, DHCPv6 clients will try the low priority server first, and then try the normal-priority routers after that.