FAQ

Contents

Environment unavailable for Resurs

Troubleshooting checklist when Resurs cannot reach your environment.

Before reporting issues to Resurs, walk through the following checklist. Many availability problems are caused by network configuration, tunneling tools, or restricted traffic.

1. Is your site available from the internet?

Ensure that your site is:

  • publicly reachable
  • correctly configured in DNS
  • accessible without VPN requirements
  • not limited to a local network

⚠️ Warning
If the environment is hosted behind a firewall or inside a private network, Resurs will not be able to access it.

See the Local Networks section for more information.

2. Are you using tunneling services or proxies?

Tools such as ngrok, LocalTunnel, or similar tunneling services act as temporary reverse‑proxy endpoints. These are:

  • frequently abused
  • considered insecure
  • blocked by Resurs’ firewall

Standard proxies used in development or staging may also fail, because proxy support is only guaranteed in production environments.

⚠️ Warning
If your integration depends on tunneling tools, temporary URL services, or non‑production proxy routes, callbacks or API requests may be automatically rejected.

3. Are you blocking or restricting inbound traffic?

Check if your firewall or web server is restricting inbound requests. Make sure that:

  • your firewall allows traffic from Resurs’ callback IP addresses
  • web server access controls are not rejecting unknown sources
  • security layers (WAF, rate‑limiting, IP filtering) are not blocking Resurs

ℹ️ Info
If inbound traffic is blocked at any level, callbacks and API communication will fail.
See the Firewall Requirements section for allowed IP ranges.

4. Are you using the correct TLS version?

Resurs requires TLS 1.2 or higher.

⚠️ Warning
Any TLS version below 1.2 is not supported. Connections will fail during the handshake.

Still having issues?

Before contacting support

  • Your site is publicly reachable
  • No tunneling services are in use
  • Inbound traffic from Resurs IPs is allowed
  • TLS 1.2+ is enabled

If all checks pass, contact onboarding@resurs.se with your environment URL, logs, timestamps, and sample requests.

How do I configure my firewall/network?

Your outbound traffic

For standard use cases, we recommend accessing Resurs Bank’s services using the FQDNs (hostnames) provided to you.

Note
This applies only to outbound traffic. For inbound traffic, reverse DNS names are not guaranteed and should not be relied upon.

Your inbound traffic

Resurs Bank sends callbacks from the following IPs. These must be whitelisted:

  • 192.121.110.100 (Resurs)
  • 13.50.187.51 (Cloud)
  • 51.21.32.255 (Cloud)
  • 51.21.206.32 (Cloud)
  • 51.21.39.192 (Cloud)

⚠️ Warning
Do not whitelist entire AWS ranges. Only allow the specific IPs above.

All callbacks are sent via HTTPS (port 443).

See Appendix A for full Resurs‑owned IP ranges.

Local Networks / Hosts

Why callbacks fail from local networks and how to resolve it.

Note
Or: “Why are my callbacks not working?”

Resurs cannot reach systems hosted behind private IP ranges or behind internal‑only DNS.

Private Networks Are Not Publicly Routable

These private IP ranges are unreachable from the internet:

  • 192.168.0.0/16
  • 172.16.0.0/16
  • 10.0.0.0/8

⚠️ Warning
Callback traffic to these addresses will always fail.

Internal‑Only Hostnames Cannot Be Resolved

Examples include:

  • local dev hostnames
  • DNS zones only available inside your LAN
  • internal domains not published publicly

ℹ️ Info
A hostname must resolve through public DNS to be reachable.

If It’s Not Publicly Accessible, It Won’t Work

If your callback URL is not reachable from the internet or not resolvable publicly, callbacks will fail.

💡 Tip
Use a publicly reachable staging environment or expose your system externally.

The Jungle of SSL / TLS Requirements

TLS Requirements

All integrations require TLS 1.2+.

⚠️ Warning
Older TLS versions fail during handshake.

SSL/TLS Certificate Requirements

Your site must use a valid and trusted certificate.

The following are not accepted:

Invalid Certificates

  • Self‑signed
  • Expired
  • Revoked

Configuration Issues

  • Wrong domain
  • Missing chain
  • Untrusted CA

ℹ️ Info
These will cause the integration to fail.

Examples of Trusted Certificate Authorities

Certificate Authority Type
DigiCert Commercial
Network Solutions Commercial
GoDaddy Commercial
Let’s Encrypt Free

Note
Not an exhaustive list.

Where Can I Find a Verified Issuer?

Commercial Providers

DigiCert, GoDaddy, Network Solutions

Cloud Platform CAs

AWS ACM, Azure App Service Certificates, Google Cloud managed SSL

Free Providers

Let’s Encrypt

Registrars & Hosts

Many hosting companies bundle SSL certificates.

💡 Tip Choose a CA trusted by major browsers.

Swish för Handel – Resurs Technical Supplier

Steps to activate Swish

  1. Verify availability with your salesperson
  2. Sign agreement with your bank choosing Resurs as technical supplier
  3. Await confirmation — Swish notifies onboarding@resurs.se
  4. Configuration — Resurs enables the payment method in production

Appendix A – Resurs owned network IP details

CIDR overview

Network CIDR-block Broadcast Netmask AS Number
192.121.110.0/24 192.121.110.255 255.255.255.0 AS35814
194.68.237.0/24 194.68.237.255 255.255.255.0 AS35814
91.198.202.0/24 91.198.202.255 255.255.255.0 AS35814

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