10 months ago
I am currently using a CNAME to point to Railway for a custom domain. However, doing this make it impossible to setup SPF records, so I need to use an A record or ALIAS instead. But what is the railway IP address that I need to use for this?
26 Replies
10 months ago
I am also in need of this for 1f7cc3a8-76f3-47c2-beba-2b5bb6e4e202
10 months ago
Running a dig against the CNAME domain the setup instructions gives me (e.g. [something.up.railway.app](something.up.railway.app)) yields this: ```❯❯ dig qt0utsxf.up.railway.app
; <<>> DiG 9.10.6 <<>> qt0utsxf.up.railway.app
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 12971
;; flags: qr rd ra; QUERY: 1, ANSWER: 5, AUTHORITY: 0, ADDITIONAL: 1
;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 1232
;; QUESTION SECTION:
;qt0utsxf.up.railway.app. IN A
;; ANSWER SECTION:
qt0utsxf.up.railway.app. 60 IN CNAME edge.railway.app.
edge.railway.app. 300 IN A 66.33.22.2
edge.railway.app. 300 IN A 66.33.22.1
edge.railway.app. 300 IN A 66.33.22.4
edge.railway.app. 300 IN A 66.33.22.3
;; Query time: 33 msec
;; SERVER: 192.168.1.1#53(192.168.1.1)
;; WHEN: Sun Apr 06 18:16:05 EDT 2025
;; MSG SIZE rcvd: 135```
10 months ago
I'm going to test my app with those 66.33.22.* IPs as @ A records and see if that works
10 months ago
Unclear if they are static IPs, but that fact that [edge.railway.app](edge.railway.app) has A records to four of them seems promising
10 months ago
Aaaaand that does not work, yields an error due to the certificate not matching the domain
10 months ago
I've been loving Railway, but unfortunately if this is not possible I will need to switch providers.
10 months ago
This is a pretty huge restriction for anything other than hobby apps -- a little upset that "Custom Domain Support" is marketed when it's not actually supported fully.
Are you sure it's not fully supported? That would be pretty insane, that means you can't even have a custom email address if the root domain is hosted on railway
10 months ago
Their docs say it isn't supported https://docs.railway.com/guides/public-networking#adding-a-custom-domain
10 months ago
They support CNAME flattening and ALIAS records, otherwise the docs say (unhelpfully) "just change your name servers!"
10 months ago
You can if your DNS provider supports it
10 months ago
I'm not going to switch my DNS provider just because a PAAS product decided to not support the most straightforward DNS mechanism for domain redirection
10 months ago
The problem is that all the mechanisms Railway supports (CNAME flattening, ALIAS records) are not standard DNS features
10 months ago
So they are not guaranteed to work with all services.
10 months ago
!s
Status changed to Solved brody • 10 months ago
Status changed to Open Railway • 10 months ago
phin
You should be able to point your apex to 66.33.22.1 and it should work.
7 months ago
Hi, I need to set up SPF records for my domain but Railway assigns dynamic IPs on each deployment.
You mentioned pointing apex to 66.33.22.1 - does this static IP also apply to outgoing emails from my app, or is there another way to handle SPF with Railway's dynamic IPs?
Thanks!
7 months ago
That IP is not used for outgoing traffic. For that, you would need to be on the Pro plan to enable static IPs.
https://docs.railway.com/reference/static-outbound-ips
brody
That IP is not used for outgoing traffic. For that, you would need to be on the Pro plan to enable static IPs.https://docs.railway.com/reference/static-outbound-ips
7 months ago
but it seems impossible due to:
Caveats
There is no guarantee that the IPv4 address assigned to your service is dedicated. It may be shared with other customers.
so it's not safe