Registered · Network

1998 Cisco XOT

TCP Yes
UDP
SCTP
DCCP

What it is

X.25 over TCP.

When / why

Legacy X.25 transport.

Protocol status detail

TransportStatusMeaning
TCP Yes Assigned by IANA and standardized, specified, or widely used on this port.
UDP Not applicable for this transport.
SCTP Not applicable for this transport.
DCCP Not applicable for this transport.

Port range

Registered (1024–49151). Assigned by IANA on request; usable without elevated privileges on most systems.

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Firewall rules for port 1998

Copy-ready inbound rules for the active transports. Replace every <source> placeholder with the specific host, subnet, or CIDR that should reach this port.

ufw

sudo ufw allow proto tcp from <source> to any port 1998

Allow TCP 1998 (Cisco XOT). Replace <source> with the network/host that should reach it.

firewalld

sudo firewall-cmd --permanent --add-rich-rule='rule family="ipv4" source address="<source>" port port="1998" protocol="tcp" accept'

Allow TCP 1998 (Cisco XOT) from <source>. Run 'firewall-cmd --reload' afterwards.

nftables

nft add rule inet filter input ip saddr <source> tcp dport 1998 accept

Allow TCP 1998 (Cisco XOT). Assumes table 'inet filter' with an 'input' chain.

iptables

sudo iptables -A INPUT -p tcp -s <source> --dport 1998 -j ACCEPT

Allow TCP 1998 (Cisco XOT). Persist with iptables-save/netfilter-persistent.

Azure NSG

az network nsg rule create -g <resource-group> --nsg-name <nsg> -n Allow-ciscoxot-1998 --priority 1000 --access Allow --direction Inbound --protocol TCP --source-address-prefixes <source> --destination-port-ranges 1998

Inbound rule for 1998 (Cisco XOT). Set <source> to a CIDR; lower priority number = higher precedence.

AWS Security Group

aws ec2 authorize-security-group-ingress --group-id <sg-id> --ip-permissions IpProtocol=tcp,FromPort=1998,ToPort=1998,IpRanges="[{CidrIp=<source-cidr>}]"

Inbound TCP 1998 (Cisco XOT). Replace <source-cidr> (e.g. 10.0.0.0/16).

GCP firewall

gcloud compute firewall-rules create allow-ciscoxot-1998 --direction=INGRESS --action=ALLOW --rules=tcp:1998 --source-ranges=<source-cidr> --network=<network>

Ingress rule for 1998 (Cisco XOT). Scope with --source-ranges and optionally --target-tags.

Windows netsh

netsh advfirewall firewall add rule name="Allow Cisco XOT 1998/TCP" dir=in action=allow protocol=TCP localport=1998 remoteip=<source>

Inbound TCP 1998 (Cisco XOT). Set remoteip to a host/subnet; 'any' is discouraged.

Windows PowerShell

New-NetFirewallRule -DisplayName "Allow Cisco XOT 1998/TCP" -Direction Inbound -Action Allow -Protocol TCP -LocalPort 1998 -RemoteAddress <source>

Inbound TCP 1998 (Cisco XOT). Replace <source> with a host or subnet.

Rules are generated only for transports marked active for this port. They default to an inbound allow with an explicit source placeholder — never any. Review direction, scope, and rule precedence before applying in production.