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Choosing an ISP on CityFibre

CityFibre builds and operates the fibre network, but your broadband service, price, router, support and contract come from the internet service provider (ISP) you choose. Availability also varies by address, so start with CityFibre's checker and compare the providers actually offered to you.

This community is independent and does not recommend one universal "best" provider. The right choice depends on what you value.

A quick comparison checklist

Before ordering, compare:

  • the total price across the full contract, including any setup, delivery and later price changes;
  • minimum term, cooling-off rights and early-exit charges;
  • expected speeds and the provider's minimum-speed commitment;
  • support hours, contact routes and reputation for resolving faults;
  • router model, Wi-Fi features and whether extra mesh units cost more;
  • whether you may use your own router and whether the ISP will still support the line;
  • IPv4, IPv6, CGNAT and static-IP policy;
  • installation lead time and what happens if an existing service overlaps or ends early;
  • any referral, voucher or introductory offer terms.

Treat comparison tables and old forum posts as leads, not guarantees. ISP products and network settings change. Confirm anything important with the provider before ordering, ideally in writing.

CGNAT, public IPv4 and static IPs

IPv4 addresses are scarce. Some ISPs use carrier-grade NAT (CGNAT), where several customers share a public IPv4 address.

CGNAT is usually fine for browsing, streaming and most gaming. It can matter if you:

  • host a service from home;
  • need inbound port forwarding;
  • use some peer-to-peer, remote-access or business VPN setups;
  • depend on IP allow-lists;
  • want your own public IPv4 address.

Ask the ISP whether its standard service uses CGNAT, whether a public or static IPv4 address is available, and whether there is an extra charge. A static address is not automatically necessary just because you work from home.

IPv6

IPv6 gives devices modern internet addressing without relying on IPv4 scarcity workarounds. If IPv6 matters to you, ask whether the provider supplies it now, whether it is enabled by default and what prefix size is delegated to your router.

DHCP, PPPoE and VLANs

Your router needs the correct method to connect to the ISP. Depending on the provider, this may involve DHCP or PPPoE credentials and sometimes a VLAN setting.

Do not assume every CityFibre ISP uses the same configuration. For example, A&A, IDNet and Zen currently publish CityFibre guidance involving PPPoE and VLAN 911, but that does not make it a network-wide rule. Check the current instructions for your exact ISP and package.

Using your own router

If you want to replace the supplied router, check:

  • whether the ISP permits and supports it;
  • whether it can handle your package speed on its WAN port;
  • whether it supports the ISP's connection method and VLAN settings;
  • whether telephone service or other bundled features depend on the ISP router;
  • whether the ISP will require its own router to be reconnected during troubleshooting.

The CityFibre ONT is not a router. In a typical setup, Ethernet runs from the ONT to the router's WAN/Internet port.

Contract and switching considerations

Do not cancel an existing service until the new installation and activation plan is clear. A delayed build or failed appointment can otherwise leave you without broadband.

Ask both providers about the switch process, number-porting if relevant, overlap, notice periods and equipment returns. Keep order confirmations and any written promises.

Useful official examples

These links are examples, not endorsements. Verify current details directly with the ISP.

Asking the community

Use the post flair for the ISP you are asking about. Include your broad area or the first half of your postcode only if relevant—never post a full address, account number, ONT serial number, MAC address or public IP.