Short version: if there is a white ONT on the wall with an Ethernet port — Open Eir FTTH, SIRO, NBI — you can bin the provider hub and plug your own router into that socket. Tag the WAN as VLAN 10. Eir and Pure (Open Eir) usually take plain DHCP; Vodafone, Sky, Digiweb and Pure (SIRO/NBI) want PPPoE with a generic login. Nobody except Digiweb will help you do it.
If the provider box is the modem — Virgin’s fibre Hub 5x, every 5G hub, Imagine’s indoor unit — you run your router behind it and live with double NAT, or switch provider. Starlink is the exception: bypass mode is a toggle in the app.
ONT vs router: the one paragraph that decides this
On full fibre there are two boxes. The ONT (optical network terminal) is the small white unit the installer screwed to the wall; it turns light into Ethernet and belongs to the network — Open Eir, SIRO or NBI — not the retailer. The router is the retailer’s branded hub plugged into it: Eir’s black box, the Vodafone Gigabox, the Sky Hub, Pure’s Zyxel, Digiweb’s Fritz!Box. Swapping the router is your business. The ONT stays. The only things the retailer’s hub knows that yours does not are a VLAN number and, sometimes, a login — and both are generic.
Where this breaks down is when one box does both jobs. Virgin’s cable Hub 5 is a DOCSIS modem with a router inside; Virgin’s fibre Hub 5x has the ONT inside it; a Three, Vodafone or Eir 5G hub is the modem because it holds the SIM. You cannot remove those. You can only put them into a modem or bridge mode if the firmware offers one, or hang your router off a LAN port and accept two layers of NAT. If you are not sure which network is at your address, check by Eircode and read Open Eir vs SIRO vs NBI vs Virgin.
Provider by provider: allowed, connection, settings, caveats
Settings below marked “reported by users” come from boards.ie and Sky Community threads between 2020 and April 2026, not from the provider’s own page — because, Digiweb and Pure aside, no Irish retailer publishes them. Networks are taken from our August 2026 provider data. The provider-supplied hubs themselves are compared in the router guide; this page is about replacing them.
| Provider (networks) | Own router? | What you connect to | Settings | Caveats |
|---|---|---|---|---|
| Eir Open Eir FTTH, Open Eir FTTC, NBI, 5G home | Yes, unsupported | Open Eir FTTH / NBI: ONT with an Ethernet port. FTTC: VDSL modem needed. | VLAN 10. DHCP/IPoE works on most lines with no username; PPPoE with any credentials also connects. Static IP needs PPPoE. (Reported by users.) | Eir support will not walk you through third-party kit. Eir voice runs through the Eir hub; TV is an app, so it survives. |
| Vodafone Open Eir FTTH, Open Eir FTTC, SIRO, NBI, 5G home | Yes, discouraged | ONT on Open Eir FTTH, SIRO and NBI. Gigabox bridge mode is unreliable or absent on recent firmware. | PPPoE + VLAN 10. Username [email protected] or the Gigabox [email protected], password broadband. (Reported by users.) | Vodafone TV is IPTV on a separate VLAN (100 reported) and usually breaks. Support will say “not trained on third-party equipment”. |
| Sky Open Eir FTTH, Open Eir FTTC, SIRO, NBI | Yes, unsupported | ONT on Open Eir FTTH, SIRO, NBI and (from 2024) Virgin’s fibre. No modem mode needed. | PPPoE + VLAN 10, username anything@skydsl, password anything. Not the UK DHCP option 61 (MER) setup. (Reported by users; confirmed on Sky Community.) | Sky Hub is loaned; keep it for the return. Sky Stream / Sky Q work over any router. |
| Virgin Media Virgin cable, Virgin fibre, SIRO, NBI | Coax: yes. Fibre: effectively no | Coax Hub 5: modem mode in the hub. Virgin fibre Hub 5x: ONT is inside the hub, no modem mode, CGNAT/DS-Lite. | Coax: 192.168.0.1 → Modem mode → your router gets a public IP, one device only. Fibre: run your router behind the hub (double NAT) or use Sky/Vodafone on the same fibre. | Support enables an IPv4/modem-mode flag on request for coax; on fibre they say business only. (Reported by users.) |
| Pure Telecom Open Eir FTTH, Open Eir FTTC, SIRO, NBI | Yes | ONT on Open Eir FTTH, SIRO and NBI. FTTC: bridge the Zyxel. | Open Eir FTTH: DHCP + VLAN 10, no login. SIRO/NBI: PPPoE + VLAN 10, [email protected] / broadband1. Zyxel has a bridge option on its WAN page. (Reported by users; bridge step on puretelecom.ie.) | Easiest retailer on this list. Support still expects the Zyxel for fault-finding. |
| Digiweb Open Eir FTTH, SIRO, NBI, Fixed wireless, Satellite | Yes, support helps | ONT on SIRO, NBI and Open Eir FTTH. FTTC: bridge the Fritz!Box. | PPPoE + VLAN 10. SIRO: [email protected] / digiweb; NBI and static IPs: [email protected] / digiweb. (From Digiweb’s Fritz!Box guide and user reports.) | Digiweb staff on boards.ie have said the support team will talk you through a third-party setup. Rare. |
| Imagine Fixed wireless, 5G home, SIRO, NBI | Partly | Outdoor 5G / fixed-wireless unit feeds an indoor Wi-Fi 7 router over Ethernet. | Plug your own router into the indoor unit’s LAN port and run it as the only DHCP server, or run mesh in access-point mode. Bridge/IP-passthrough depends on the router model supplied. (Reported by users.) | Equipment stays Imagine’s for 2 years; unreturned-equipment charge up to €150 (Oct 2025 price guides). |
| Three 5G home | Partly | The 5G hub (ZTE) is the modem. Outdoor-antenna installs use a ZTE MC7010 outside bridged to a T3000 router inside. | Bridge/IP passthrough on the hub where the firmware offers it, otherwise double NAT or mesh in AP mode. Port forwarding is typically dead behind mobile CGNAT anyway. (Reported by users.) | You cannot replace the hub with a fibre router — it needs the SIM. A third-party 5G router with the Three SIM is the real swap. |
| Vodafone GigaCube 5G home | Partly | Huawei H155-383 5G CPE is the modem. | No true bridge mode on the consumer firmware we could confirm. Turn off its Wi-Fi and DHCP and let your router NAT behind it, or run mesh in AP mode. | Double NAT. Fine for streaming and WFH; a pain for hosting anything. |
| Eir 5G Home 5G home | Partly | Huawei Wi-Fi 6 5G router with two gigabit Ethernet ports is the modem. | Same pattern as GigaCube: hub stays, your router or mesh sits behind it. (Reported by users.) | No €99 device fee on the 12-month plan, but the unit is still theirs to ask back. |
| Starlink Satellite | Yes, designed in | Gen 3 Standard kit: router has two LAN ports behind a cover. Older Gen 2 rectangular dish: needs the Starlink Ethernet Adapter. | Starlink app → Settings → Bypass Mode. Starlink Wi-Fi switches off; your router gets the connection on the LAN port. Factory-reset the Starlink router to undo. | Still CGNAT on residential. Bypass mode loses the Starlink router’s Wi-Fi entirely, so your own must cover the house. |
NBI: the ONT is NBI’s, the login is the retailer’s. Vodafone on NBI is PPPoE/VLAN 10 (some users needed the [email protected] form); Digiweb on NBI is PPPoE/VLAN 10 with [email protected]; Eir and Pure on NBI follow their Open Eir patterns above. If you are picking a retailer partly for this, the best NBI provider and best SIRO provider pages weigh it alongside price.
Open Eir, SIRO and NBI: the settings in detail
Every Irish FTTH network hands the retailer’s traffic to the ONT on VLAN 10. That is the setting people miss. In most routers it lives under WAN → VLAN ID, or on Asus under LAN → IPTV → “Internet” VID. Once the tag is on, the difference between retailers is only whether the line is authenticated by PPPoE or just hands out an address by DHCP (IPoE).
- Eir (Open Eir FTTH, NBI): VLAN 10, then DHCP. Users who moved from Vodafone to Eir on pfSense report not changing a thing except dropping the username — “you don’t need username or password”. If DHCP stalls, PPPoE with any credentials (the old [email protected] / broadband1 pair is still quoted) connects. A static IP from Eir needs PPPoE. One reported wrinkle: plug the Eir hub in for a few minutes on a brand-new line before swapping, so the circuit activates.
- Vodafone (Open Eir FTTH, SIRO, NBI): PPPoE on VLAN 10. Generic login [email protected] / broadband is the most-repeated working pair; an NBI user and a Vodafone agent in support both gave the Gigabox serial (starts with E) followed by @vfieftth.ie / broadband. Vodafone TV arrives as IPTV on VLAN 100 and needs a second tagged interface, which most consumer routers cannot do. If the first attempt fails, leave the Gigabox unplugged for 30 minutes before retrying — users report the network takes that long to forget the old MAC.
- Sky (Open Eir FTTH, SIRO, NBI, Virgin fibre): PPPoE on VLAN 10, username anything@skydsl, password anything — literally any string. This is the Republic of Ireland setup and is different from Sky UK, where third-party routers use DHCP with option 61 (MER). Guides that tell you to set option 61 are for the UK; if your router only offers MER, it will not authenticate here.
- Pure Telecom (Open Eir FTTH, SIRO, NBI): Open Eir: VLAN 10, DHCP, nothing else. SIRO and NBI: PPPoE, VLAN 10, [email protected] / broadband1, auto-connect. Pure’s Zyxel support page shows a “Type: bridge” option on the WAN entry if you want to keep the Zyxel as a dumb modem instead.
- Digiweb (SIRO, NBI, Open Eir FTTH): PPPoE, VLAN 10. Its Fritz!Box quick-start lists [email protected] / digiweb; a SIRO-specific [email protected] / digiweb is also in circulation. One installer found the nga login was the one that pulled the customer’s static IP. Digiweb staff posting on boards.ie said support will talk you through it.
FTTC is different. If your “fibre” comes over the old copper pair (Open Eir FTTC — the FTTH vs FTTC page explains how to tell), there is no ONT. You need a VDSL modem: either bridge the supplied hub and put your router behind it, or buy a router with a VDSL port. Same VLAN 10, same PPPoE logins. A cable router with only an Ethernet WAN will do nothing on FTTC.
Virgin Media: coax Hub 5 vs the fibre Hub 5x
Two completely different answers under one brand. On the coax (cable) network the Hub 5 has a proper modem mode: log in at 192.168.0.1 with the password on the base, switch mode, reboot, and the single device plugged into LAN 1 receives the public IPv4 address. Virgin has in the past needed to flip an “IPv4” flag on the account first; users say a phone call does it, with a reset of the hub if the option still does not appear. Only one device works in modem mode, so that device is your router, not a switch.
On Virgin’s own fibre (the build replacing coax from 2023, plus the 2 Gb and 5 Gb tiers on SIRO), the Sagemcom Hub 5x has the optical termination inside the case. There is no Ethernet ONT to move to, the line is DS-Lite with carrier-grade NAT, and modem mode is missing. Users who got support to enable it in 2024 needed to clone the hub’s MAC on their own router and then turned it off again for stability; by mid-2025 support was telling customers it is business-only. The enthusiast workaround — an XGS-PON SFP stick in your own router — is real but is not consumer advice. The consumer fix is to order Sky or Vodafone on the same Virgin fibre: they install a standard ONT with an Ethernet port and the table above applies. Head-to-head: Sky vs Virgin Media.
5G hubs and Starlink: the box is the modem
Three 5G, Vodafone 5G (the old GigaCube) and Eir 5G ship a Huawei or ZTE CPE with the SIM inside. That unit is the modem and the router at once. Some firmware exposes a bridge or IP-passthrough setting that hands the mobile-network address to a single device; some does not, and Three’s outdoor-antenna installs already use that trick internally (a ZTE MC7010 on the wall bridged to a T3000 inside, which is why users can swap the T3000 for their own router). Where there is no passthrough, switch the hub’s Wi-Fi off, plug your router or mesh into a LAN port, and accept double NAT — or run the mesh in access-point mode so there is only one NAT layer. Because the mobile networks typically sit behind CGNAT anyway, you lose little: inbound port forwarding was never going to work. If a hub-free setup matters, the honest route is a third-party 5G router with the Three SIM in it, which is outside what Three supports. How 5G compares on price: Three 5G vs GigaCube vs Eir 5G.
Starlink is the friendliest of the lot. The Gen 3 Standard kit’s router has two Ethernet LAN ports behind a pop-off cover; open the app, Settings, toggle Bypass Mode, and the Starlink Wi-Fi goes dark while your router takes the connection. Older Gen 2 rectangular kits have no Ethernet port at all and need the Starlink Ethernet Adapter from the Starlink shop before bypass is useful. Bypass is undone by factory-resetting the Starlink router. You are still behind CGNAT on residential, and the €35/€55/€75 rolling plans do not change. Starlink vs the fibre alternative: Starlink vs NBI.
Imagine sits between the two. The outdoor unit on the gable does the radio; the indoor Wi-Fi 7 router is an ordinary router on Ethernet. Users run their own mesh behind it either as an access point or as the only DHCP server with the Imagine router’s Wi-Fi off. Whether you can get a true passthrough depends on the model Imagine supplied. Either way, the indoor box goes back when you leave — see below.
What breaks when you swap the hub
| Feature | Own router on the ONT | Own router behind the hub |
|---|---|---|
| Landline / VoIP (Eir, Vodafone, Pure “+ phone”) | Breaks. The phone port is on the provider hub and registers with their voice platform. | Works — keep the handset in the hub. |
| Provider IPTV (Vodafone TV) | Breaks unless your router can run a second tagged VLAN (100 reported) with IGMP. Users who managed it said Vodafone support changed something the next day. | Works if the set-top box stays on the hub. |
| Streaming TV (Eir TV app, Sky Stream/Q, Virgin TV 360 app, NOW) | Works — it is just internet. | Works. |
| Provider app / parental controls / Wi-Fi pods | Gone. Use your router’s own. | Mostly gone for devices behind your router. |
| Fault support | “Plug our hub back in first.” Every provider; Digiweb is the exception that helps. | Same, but the hub is already there. |
| Port forwarding, UPnP, game consoles | Works on fibre (real public IP). Not on CGNAT lines (Virgin fibre, 5G, Starlink). | Double NAT: needs the same rule on both boxes and often still fails. |
Speed is the other casualty people do not expect. A 2015 router that was grand on 100 Mb will NAT a 1 Gb line at a few hundred megabits, and PPPoE costs more CPU than DHCP — a Wi-Fi 7 mesh user on Eir 5 Gb saw 5 Gb for ten minutes and 4.3 Gb once the CPU warmed up. If you are not getting the number you pay for after the swap, read not getting the advertised speed before blaming the line; if the rooms upstairs are the problem, that is a Wi-Fi dead zones question, not a router-swap one.
Returning the hub when you cancel
| Provider | Who owns the hub | If you do not send it back (August 2026) |
|---|---|---|
| Imagine | Imagine, for 2 years from delivery; then yours (General T&Cs, 30 Oct 2025). | Return within 14 days of the agreement ending. Unreturned-equipment charge listed as up to €150 in the Oct 2025 fibre and 5G price guides. |
| Virgin Media | Virgin. “Equipment remains our property.” | After the 30-day notice Actavo arranges collection; Virgin “charges for anything unreturned” — no euro figure on the support page. |
| Sky | Sky, loaned. | Returns packaging is sent near the end of the notice period; a non-return charge follows if it never arrives. Keep proof of posting. |
| Vodafone, Eir, Pure, Digiweb | Varies by order; typically loaned but rarely chased. | Check the order summary. Do not assume — a €29.95 Digiweb setup fee does not make the Fritz!Box yours. |
| 5G hubs (Three, Vodafone, Eir) | Provider’s, unless you paid a device fee. | Return on cancellation; Imagine-style charges are typical. The no-contract 5G terms spell out the wrap-up charge. |
| Starlink | Yours — the kit is bought or on a promo that converts to yours. | Nothing to return; resell it or keep it as backup. |
The practical rule: the day your own router goes in, the provider hub and its power supply go into the box it came in, with the Ethernet cable, on a shelf. It is your fault-finding tool while you are a customer and your €150 when you leave. If you are leaving mid-term, the hub charge sits on top of any early-termination fee.
What to buy: a router that suits Irish lines
- VLAN tagging on the WAN port. Non-negotiable on Open Eir, SIRO and NBI. Some cheap routers and older mesh kits hide it or lack it; check the manual for “VLAN ID” or “802.1Q” on the Internet/WAN page before you pay.
- PPPoE with hardware acceleration. Needed for Vodafone, Sky, Digiweb and Pure on SIRO/NBI. Look for “NAT acceleration” or “hardware offload” and make sure it stays on with PPPoE; on one Asus it had to be toggled off and back to auto before the full 500 Mb showed up.
- VLAN + DHCP at the same time. Eir and Pure on Open Eir are DHCP. At least one popular mesh (eero) forces PPPoE once VLAN is set; it still connects, but you are paying the PPPoE tax for nothing.
- 2.5 GbE WAN for 1 Gb and above. A 1 GbE port caps at roughly 940 Mb; Vodafone’s 2 Gb, Sky/Eir/Virgin 5 Gb and Digiweb’s 2 Gb NBI/SIRO need 2.5 or 10 GbE on the WAN and on at least one LAN port. A Cat5e flylead from the ONT is fine to 2.5 Gb; an old two-pair cable will quietly give you 95 Mb.
- Wi-Fi 6 minimum, Wi-Fi 7 for 2 Gb+. The line is rarely the bottleneck in an Irish house; the radio is. If the point of the swap is coverage, spend on a mesh with Ethernet backhaul rather than a bigger single box — the dead zones page covers that trade.
- Ethernet WAN, not VDSL, unless you are on FTTC. “Cable router” or “fibre router” in shop language. A VDSL router’s DSL port is dead weight on an ONT.
- Not the hub from your last provider. Locked firmware usually will not let you set VLAN or a foreign PPPoE login, and it is probably still theirs anyway.
None of this changes which line you should buy. Pick the network and the contract first on the best broadband in Ireland ranking, then check the row above for how easy the hub is to get rid of. If two retailers are close on price, the one that takes DHCP on VLAN 10 and answers the phone — Pure or Digiweb — is the one to choose for a house full of your own kit. For what the supplied hubs are actually like before you decide to replace one, see the provider router guide.
