A guide for changing b4's firewall and network-routing state, including iptables, nftables, packet marks, route tables, NAT, and traffic capture rules. These are operating-system rules that control how network packets are filtered and routed.

Use it when modifying firewall chains, routing rules, packet marking, NAT, TPROXY, tunnel capture, or the monitor that restores those rules.

It keeps changes consistent across b4's supported networking backends and explains rule ordering and deletion, where an incorrect order can change network behavior.

How DanielLavrushin/b4 configures Claude Code

About the project

B4 is a Linux network packet-processing service that changes network traffic so deep packet inspection systems cannot identify or block its connections. It is used on routers, servers, and desktops to bypass DPI-based blocking, and a router installation can cover devices across the local network. The catalogue lists 12 skills associated with B4.

DanielLavrushin/b4 · 1,848 stars · on GitHub · docs.b4core.app

Reuse

Borrowing it

Nothing to install: this file belongs to DanielLavrushin/b4. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file

curl -O https://raw.githubusercontent.com/DanielLavrushin/b4/main/.claude/skills/b4-tables/SKILL.md

Clone the repo

git clone --depth 1 https://github.com/DanielLavrushin/b4

Made for: Claude Code.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

README.md

[![agentmods](https://agentmods.dev/badge/skills/daniellavrushin/b4/b4-tables/github.svg)](https://agentmods.dev/skills/daniellavrushin/b4/b4-tables)

Your own site

<a href="https://agentmods.dev/skills/daniellavrushin/b4/b4-tables"><img src="https://agentmods.dev/badge/skills/daniellavrushin/b4/b4-tables/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

Your own site · 80×15

<a href="https://agentmods.dev/skills/daniellavrushin/b4/b4-tables"><img src="https://agentmods.dev/badge/skills/daniellavrushin/b4/b4-tables.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 125 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 1,926 The whole file, excluding the scripts and references it only reads on demand.

Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.

Origin unknown No closer match found in the catalogue.

Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

Model	Per session	Once invoked
Fable 5.1	$0.00125	$0.01926
Opus 5.5	$0.00050	$0.00770
Sonnet 5.5	$0.00025	$0.00385
Haiku 4.5	$0.00013	$0.00193

Measured 6d ago against content hash 98060bfb4631, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

b4-tables scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 6d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

.claude/skills/b4-tables/SKILL.md · 116 lines

The source is not reproduced here

Licensed GPL-3.0

The repository is licensed GPL-3.0, which this catalogue does not treat as permission to reproduce the file. Read it at the source.

Read it on GitHub

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

6d ago First seen · 116 lines · 125 tokens per session scan A 98060bfb4631

Subscribe to this mod's changes

b4-tables is a skill published in the GitHub repository DanielLavrushin/b4 (1,848 stars, last pushed 4d ago), licensed GPL-3.0. It adds 125 tokens to every session and 1,926 once invoked, about $0.0005 per session on Opus 5.5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-10-31.

DevOps and cloud asuswrt asuswrt-merlin censorship censorship-free dpi geosite

b4-tables next to 6 skills from other repositories
Mod	Type	Stars	Last push	Licence	Scan	Tokens	Works with
b4-tablesDanielLavrushin/b4	Skill	1.8k	4d ago	GPL-3.0	A	125	Claude Code
bibavpn-setupEljaja/BibaVPN	Skill	61	6d ago	MIT	A	62	Claude Code, Codex
Xrayebator: your own VPN on a VPS (Xray Reality)howdeploy/deploychan_mcp	Skill	21	9d ago	MIT	B	60	Claude Code, Codex
imagegenopenai/codex	Skill	133k	yesterday	Apache-2.0	A	113	Codex
playwright-climicrosoft/playwright	Skill	99k	yesterday	Apache-2.0	A	19	Claude Code
local-ai-agentsmicrosoft/ai-agents-for-beginners	Skill	79k	4d ago	MIT	A	200	Claude Code, Codex
systematic-debuggingobra/superpowers	Skill	313k	3d ago	MIT	A	21	Claude Code

b4: Skill for Claude Code