tcp-ping-port
v1.0.2
Published
A simple TCP ping utility to ping a port of an IP or domain
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Readme
tcp-ping-port
A simple TCP ping utility to ping a port of an IP or domain.
Table of contents
Benefits
Following are the pros and cons of this package compared to the regular ping
Pros
- Can be used with Amazon Lambda functions and Aazure functions.
Regularping
uses ICMP protocol which is not permitted by AWS/Azure functions - TCP packets have higher priorty than ICMP packets
- It can ping a particular port
- It can work even if ICMP is disabled
Cons
Higher data usage
| Protocol | Send (B)) | Receive (B) | Total (B) | Data saving | | -------- | --------- | ------------ | ---------- | ----------- | | TCP | 228 | 126 | 354 | 0% | | ICMP | 98 | 98 | 196 | 45% |
The numbers are based on data reported by Wireshark
TCP Ping
| No. | Time | Source | Destination | Protocol | Length | Info | | --- | ---- | ------ | ----------- | -------- | ------ | ---- |
| 1 | 0.000000 | x.x.x.x | y.y.y.y | DNS | 70 | Standard query 0xfe55 A google.com | | 2 | 0.000393 | y.y.y.y | x.x.x.x | DNS | 86 | Standard query response 0xfe55 A google.com A 172.217.165.14 | | | | | | | | |
| 3 | 0.001364 | x.x.x.x | 172.217.165.14 | TCP | 66 | 49985 → 80 [SYN] Seq=0 Win=64240 Len=0 MSS=1460 WS=256 SACK_PERM=1 | | 4 | 0.012339 | 172.217.165.14 | x.x.x.x | TCP | 66 | 80 → 49985 [SYN, ACK] Seq=0 Ack=1 Win=65535 Len=0 MSS=1430 SACK_PERM=1 WS=256 | | 5 | 0.012412 | x.x.x.x | 172.217.165.14 | TCP | 54 | 49985 → 80 [ACK] Seq=1 Ack=1 Win=262912 Len=0 | | 6 | 0.013110 | x.x.x.x | 172.217.165.14 | TCP | 54 | 49985 → 80 [FIN, ACK] Seq=1 Ack=1 Win=262912 Len=0 | | 7 | 0.024927 | 172.217.165.14 | x.x.x.x | TCP | 60 | 80 → 49985 [FIN, ACK] Seq=1 Ack=2 Win=65536 Len=0 | | 8 | 0.024987 | x.x.x.x | 172.217.165.14 | TCP | 54 | 49985 → 80 [ACK] Seq=2 Ack=2 Win=262912 Len=0 |ICMP ping
| No. | Time | Source | Destination | Protocol | Length | Info | | --- | ---- | ------ | ----------- | -------- | ------ | ---- |
| 1 | 0.000000 | x.x.x.x | y.y.y.y | DNS | 70 | Standard query 0xff9e A google.com| | 2 | 0.003286 | y.y.y.y | x.x.x.x | DNS | 86 | Standard query response 0xff9e A google.com A 172.217.165.14| | 3 | 0.040291 | x.x.x.x | 172.217.165.14| ICMP | 98 | Echo (ping) request id=0x0279, seq=1/256, ttl=128 (reply in 6)| | 4 | 0.064258 | 172.217.165.14 | x.x.x.x | ICMP | 98 | Echo (ping) reply id=0x0279, seq=1/256, ttl=112 (request in 5)|NOTE: The first 2 DNS resolution calls are same in both cases for IPv4 and are not included in the total data usagage.
Installation
$ npm install tcp-ping-port --save
How to use
Simple examples
const { tcpPingPort } = require("tcp-ping-port")
tcpPingPort("google.com").then(({online}) => {
// ....
})
With additional options
const { tcpPingPort } = require("tcp-ping-port")
const dns = require('dns')
const options = {
socketTimeout: 11000,
dnsTimeout: 10000,
dnsServers: '8.8.8.8', // google DNS
}
tcpPingPort("google.com", 80, options).then(({online, ping}) => {
// ....
})
Check if host is offline
const { tcpPingPort } = require("tcp-ping-port")
tcpPingPort("google.com").then(result => {
if (!result.online && result.error.code === 'TCPPINGTIMEOUT') {
// your code when host is not accessible....
}
})
Dependencies
dns-fast-resolver
- to resolve multiple domains at the same time and to handle any errors while resolving the domain name. Also, to skip the whole dns resolution if host name is an IP address.lodash
maketype
API
tcpPingPort(hostname[, port, options, resolver])
Attemps to open and close TCP connection
- hostname
<string>
Host name or an IP address to try to connect to - port
<number>
Port number - options
<Object>
Socket and Resolver options- socketTimeout
<integer>
Number of milliseconds to wait before the resolving request is canceled. Default value 4000 (4s). - dnsTimeout
<integer>
Number of milliseconds to wait before the resolving request is canceled. Default value 4000 (4s).
Usefull for rare cases when hostnames may need more than default 4 seconds to be resolved. - dnsServers
<string[]>
Array of RFC 5952 formatted addresses. (Example:['4.4.4.4', '[2001:4860:4860::8888]', '4.4.4.4:1053', '[2001:4860:4860::8888]:1053']
)
- socketTimeout
- returns
<Promise<Result>>
Promise that will return online status ofhost
.Result
propertiesonline
- indicates if host is onlineTrue
- when host is online and TCP connection is successfully opened and closedFalse
- when host name is not resolved or it failed to open a TCP connection. CheckResult.error
for details.
ping
- returns duration (latency) of the ping in milliseconds.error
- returns error causing thehost
to be flagged as offline. Useful in verifying thehost
is offline.host
- hostnameport
- portip
- DNS Resolved IP address of the hostname
Testing
Run all tests
$ npm test
Run individual test ping "google.com:80"
$ npm run unit-test -- --grep "google.com:80"